I applaud both you and your DH in putting his failed family spawn in her place.  
 

The best  way to counter her toxicity is for you and your DH to focus on your marriage.  As you do this his clarity will improve and her ability to manipulate will diminish.

Living well in full view of the toxic opposition in the blended family world is the best revenge. It also provides an example.  Whether to follow that example or not is the choice of those suffering the revenge you are applying by living well.

I don't buy the "completely defenseless" defense. Only child or not, he the father and if his daughter cannot abide by his wishes to stop bad mouthing his wife to him, he needs to put her in her place, even if that means walking away from the conversation.

You can choose to not have a relationship with her, you can choose to not have her in your home, but I don't think it would be wise to tell him that HE cannot see her. Demanding something like that can really backfire. Instead of realizing that his daughter is poison, he will miss her, and will blame YOU.

He needs to be the one to cut or lessen contact, if she persists in trying to turn him against you. If it's forced by you, making you the bad guy, she gets what she wants, as he will eventually resent you for it. He will then forget HER antics, but he will remember that you came between him and his daughter.

Would he be open to therapy, to learn how to deal with his manipulative daughter? It has to be the right therapist.

Otherwise, you have to trust that your bond with your husband is strong and that he is strong enough to not be swayed by her. Which, it sounds like you think that he might not be that strong and that's a scary place to be but if that's the case, it will happen, one way or another.

I wouldn't stop him from going to see her on his own but I certainly wouldn't have somebody who's openly hostile to me come to visit in my house.

You've gotten some good suggestions here although a few are contradictory to others. This is what makes it hard trying to figure out what to do.

Ultimately, yes, deep down many of us wish our toxic skids would just be cut off and never be heard from again. That's a fantasy and the reality is that parents (usually guilty fathers) will never give up even the most fragile thread to their adult kids no matter what lousy people they turn out to be. That's human nature and you cannot change it.   So you are not alone in feeling that way and its OK. Just keep that feeling to yourself or vent it out here on STalk. 

My caution is this: I don't know how old you are and will assume you are similar in age to your husband - late 50s. If this is the case then you need to be very cognizant that your future lifestyle and well-being may depend on what your husband does.  This is where it can be scary. 

Your husband may do all the right things now but when faced with a serious illness or becomes more frail, he may cave in to his daughter's demands.  Likewise, if YOU become incapacitated your well-being and care may hinge on his daughter's influence. This is where you need to make very clear, and very legal, boundaries. 

I would have a serious talk with your DH. Tell him that you fully support him maintaining a relationship with his daughter but you have legitimate, proven concerns that she is interested in influencing his finances and that will most certainly negatively affect you, his wife, since she has made it clear she can't stand you. 

Make an appointment to visit an attorney and get finances, wills, power of attorney, end of life decisions, etc. all spelled out to both of your satisfaction.  Be sure to ask if the documents will be able to withstand his daughter's attempts to make him change his due to guilt or manipulation if he becomes weak or seriously ill.  You don't want to spend years caring for him only to find she got him to change his will a couple of months before he passes.  Likewise, you want to make sure that she cannot inflluence what happens to YOU if you need care and your DH cannot do it on his own.  I'm sure she'd have you dumped on the door of the nearest poor house. 

To me, these are the matters of primacy. The other stuff is a matter of practice.  You can learn to disengage and STOP ASKING QUESTIONS about what DH talks about when he visits his daughter. If he begins to tell you what she says without you asking, then tell him to stop doing it. You already know she bad mouths you don't expect that to change. She will not grow up and she will not change.

While I agree that a 58 year old man should be able to stand up for himself and SOLIDLY shut her down, the fact is that this is probably not going to happen. This is his only child and grandchildren.  He will not issue ultimatums. He probably is well aware of what his daughter is doing (I know my SO is) but will not stop it because he will hang on to any shred of connection no matter how much it hurts him.  Which includes listening to her bash you over and over again. 

I don't know if your DH has other family members you are close with, and have a good relationship with. His siblings, nieces/nephews, etc.  If you can maintain a good relationship with other relatives, that may help balance things in the long run against SD's toxicity.  Do not bash SD to them, nor gossip about her...act as though she doesn't exist. Keep a positive relationship with friends/relatives and that may help in the long run.

I wish you well. It's not an easy road, is it? 

Can you elaborate what that means. How is this so because she is the only kid? How would a grown man be completely defenseless against her? Doesnt make sense to me.

She sounds shitty to the max. Not sure why DH bothers to tell you the shitty things she says. Also why would your DH want to spend time with someone who constantly insults his WIFE. I get that she is his DD but she is a disrespectful twat to your DH and you. 

Others have a great detailed list of advice, ranging from consult with an attorny as regards inheritance, power of attorney and how to deal with toxic visitations with SD.

1. Consult with an attorney and estate planners. Get YOUR future ducks in a row. SD certainly has made it PERFECTLY clear what her intentions are.

2. Talk with your husband. You really do not need to hear all about the toxic drivel that SD is producing, do you? If he cant put a stop to it, that doesnt mean you have to know about it.

3. Keep supporting your husband in his visitations. Focus on what you can control which is your marriage and relationship. The others are so right - if you attempt to curtail these, then you WILL become the enemy.

4. Keep/develop a strong support system.

You are not alone in your feelings - I too have battled an SD who was very toxic about me. She no longer lives with us - her toxic resides with her mother, Toxic Troll. Feral Forger SD22 will never live with me again, but I still support Husbands visitation with her. Have even orchestrated a few myself. I am disengaged now.

As she puts it, "it's all mine", so has gone out of her way to treat my husband very badly because he sides with me and chooses me.

Did some of you miss this statement? Her SD has gone out of her way to treat her DH badly. The reason doesn't matter. Why would she support her DH in his visitations or support him being in a toxic relationship with his DD or anyone else for that matter? Is that the advice you would give to one of your adult kids, a niece, or a best friend? I  don't know any men that would give such horrible advice to his daughter, niece, sister, friend etc. In fact, noone ever gave me that kind of advice, not even the women in my life (friends and family). 

Do some people want to be married that much they will just tolerate any old bs a man brings to the relationship? MEN don't allow anyone to emasculate them, especially a piece of shit of a daughter. My male friends and family would put their foot so far up their DD's a$$ that it would get stuck if she ever disrespected them or their wives/partners.

Original poster, how long have you been married? Don't believe for one second your SD just started treating her father like that. She has likely ALWAYS treated him like that. This isn't your problem. It is HIS problem, and I sure as hell would be DEMANDING he fix it or I would be gone. 

But, my husband  will see her, whenever it's agreed upon, by himself.  

HELL NO. Real men don't let anyone divide them from their partner. What is the problem that he hasn't taught her she isn't in control of him?  He should tell her to straighten her a$$ up or he will leave her zero inheritance.

My husband is COMPLETELY defenseless against her as she is his only child.

Do you really believe this??? If your DH is so defenseless why did he get married when one of his obligations is to protect his wife? Why would you even settle for someone like this?  How can any man be afraid of his kid? Like, how could any woman be attracted to someone like that, let alone respect him?

Original poster, life is so short. Don't let your DH and SD make life harder for you than it really has to be. You are HIS wife. If he can't value you as such, why stay?

My SO has a DD22 who is mentally unstable and pretty horrible to him most of the time. When I met him he excused all her behavior, but since then he seems to be seeing the light, very slowly. I never told him what he could do or not do, no threats ever. But I have consistently told him what I think. It started with comments like "wow, I would never let my kids treat me that way" and over time, it's become more specific. In the last round of her abusing him, I told him that seeing him mistreated was hard for me and I would "prefer" that he minimize contact until she demonstrates that she can treat with him kindness and respect. In the end, it's up to him, but he knows how I feel. In that recent situation, he agreed with my suggestions and made some changes to minimize contact. Time will tell what happens next. Keep telling your husband what you prefer, what you need. If he loves you and your requests are reasonable, he should be making every effort to honor them. You have every right to protect yourself, emotionally, mentally and financially.

When we're discussing SD, I try to speak respectfully (for the most part) and final decisions are always up to him. He will never have to choose between us or anything, but I did insist on boundaries about 1.5 years into our relationship which he has established and honored. She is not allowed in my home (we live separately for now), her antics cannot have a negative affect on me or my family. He understands and has made that work. He will ask my opinion about a certain situation and how he should respond and he takes my input into this thought process. But final decisions are his. I get very curious about details, but bite my tongue vs. asking as I don't want to give her the power of taking my energy.

We have been working on legal issues because I do not want to deal with her should something happen to him. I have his POA- healthcare and POA-finances, and I am beneficiary on a life insurance policy. As of now, the rest of his assets will go to his kids via a trustee as I do not want to have to deal with her or help them sort it out if something happens to him. At this juncture, I want nothing to do with her ever. My SO has a son who is fine and I have no issues with him at all. If, by chance, she matures and gets her act together and can treat him and me with respect and consideration, then I'm sure he would welcome a better relationship. But I don't think he's hoping or expecting that. Over time, he seems to be making peace with the truth about her and their relationship. 

I encourage you to have honest conversations with your husband about this. Put boundaries in place, make sure you are protected legally and financially. If he thinks this is unnecessary or over-reacting, then do it yourself and make it very clear to him that you WILL be looking out for yourself and your well being, even if he isn't. 

I am in a somewhat similar situation and it is extremely frustrating to say the least. From my POV, SD should spend her time worrying about her own career and building her own finances instead of counting her father's money. We took inheritance off of the table a long time ago. DH and I earn a similar income and whatever is left will go to charity. I know that doesn't work for everyone and not everyone will agree, but I think getting this topic out of the way early can help you build more authentic bonds and help skids understand that they need to work hard and make it on their own. It doesn't mean you can't help them, but it does mean that you have made it clear that your money is your money and they don't ever need to worry about how you spend it.

From a broader perspective, yes she will absolutely try to manipulate him. She will try and your instincts will be to try to stop her but you can't. If you try to block him from seeing her it only gives her more power and ammunition to push her own agenda and make you the outsider who is "driving their family apart". I have one of them in my life too and as much as I hate it, and I mean hate it, I try to bite my lip when he spends time with her and instead call up a friend or do something fun to distract myself. I didn't hide my displeasure as well in the past and it eventually made him feel like I was trying to control him and that resentment led to its own set of problems and it made me pretty miserable as well.

I have, however, banned her from my home. I can't control who DH keeps in his life but I can control who is in mine. It has come with its own entire avalanche of problems - hence why I am here -so I am the last person who should be giving advice but I just wanted to drop a note to say I understand where you are coming from and it sucks. 

As difficult as it is, try to take your focus off of what you can't control and focus on what you can control - getting your ducks in a row legally and making inheritance a permanent non issue. Best of luck!

This sounds so familiar with my SD. She's manipulative and about NOTHING but monetary gain with her dad. I think I have finally gotten through to him and he has an understanding that NONE of us were meant to completely give up ourselves, our liveliehood, and our time to our grown children. We raised them, educated them, and support them from afar. We are NOT to lay down the red carpet for them and give up everything of ourselves to them until we are drained and dead. She has to understand that her dad is not an extension of her wallet. That he's a human and has boundaries. And if she doesn't like it, TOO BAD!