Thank you for your response.  I know (or hope) this is the age and part of grief.  I try to remember it's not personal.  But even before BM passed she (like her BM) showed these characteristics.  Maybe I'm not giving enough grace.  I know she is grieving.  But I can't get her to take any responsibility.  She complains about her back hurting, she wants a quick fix.  But that's not life.  She hides junk food in her bedroom (no idea how she is buying it), eats crap, she's overweight, she sits in her bed a lot or walks hunched over.  I tell her if you want your back to stop hurting you need to do your stretches, try to strengthen your core, work on your posture and use your desk (I don't discuss her weight, just remind her what she eats is what she will feel. So you eat crap you will feel like crap).  I offer to do these things with her.  Her response...that won't do anything.  We've tried group counseling, she refuses to go.  We've tried getting her involved in activities before and after BM passed.  Her BM would pull her out, now she refuses to do anything.  We take away her electronics she will just sleep all day.  When we try to get her out of her room we end up fighting and she refuses to come out or she claims she has bad cramps...she uses this excuse regularly.  She then claims she's depressed, miserable and scared bc of me and her father.  Same crap she would pull when BM was alive.  If she got in trouble, we would discipline her (it's called parenting)  she would call her BM claiming she was scared.  Then BM would call DH tell him he's a horrible father, SD feels scared (scared bc we took away her electronics...really) like she did when they were married...such b.s. so eventually DH would unground her follow by kissing SD's and BM's butt for weeks doing and getting them whatever they wanted to prove he was a good father. BTW if any mother thought their child was in danger you really think they would let them stay every other week at that parents house? Such a scam.  We are trying but she just wants to put all the anger, blame and issues on us.  I just don't know what to do.  What's worse giving in and letting her hang with friends so she has an outlet (and we also get a break) where she might party or letting her sit in her room all day depressed and sleeping.  What if she is suicidal? She's never said she was, we ask a lot.  But usually the quiet ones are the ones that act on it.  I just am lost.  How to parent a teenager who lost their mom is so hard.  We hear...be sympathetic, kind, forgiving BUT you must still parent.  Well how in the hec do you do that?  

Thank you all for the very helpful tips!!! Unfortunately I do have cameras bc I had to use them when SS was in his phase (he was stealing).  So I'll get them back out for me and DH's protection.  I know all about PAS, and that's exactly what it is. BM told DH when he divorced her 14 yrs ago that she will make it her mission to make sure his kids hate him.  Before she passed she even told SD that DH was hitting on her and wanted her back making her uncomfortable.  Even told SD DH told her he missed her big breast (she had a double mastectomy 13 yes before). WTF, who does this to a child.  It's absolutely not true but so messed up. She has mentally abused them for years to get back at DH and her dying mission was fo try and break us up through using her own daughter. 

SD is on medication (and birth control for cramps) and sees a therapist but I like the idea of talking to them about insight (if she allows it, can't believe 15 year olds can control their meds and control talking to their therapist).  Also thanks for the info on curfew, new full time mom here so learning.  I can't prove BF parents let them drink, she just says 'BF's parents don't care if BF drinks, and when she wasn't grounded she was always at BF's, always and she would come home looking very rough.  So putting two and two together but not sure how to prove it. 
 

I won't give up on her, sometimes I want to but I would never do it. SS was really bad and now he's an amazing, hardworking, loving young man heading to college soon.  I did send him to a outdoor camp for a month when he was this age and he came back a totally different person (against BM's wishes and with a lot of pushback).  But SD refuses to go. We are contemplating boarding school.  Only bc She just has been taught to hate us that I don't think we can get her the support she needs.  Also any relationship with me would be against her mom (her mother apparently made it clear she hated me before she passed, even though I did nothing to this woman but support her and her kids). Think only time and maturity will make her see we really love her and we are good people. 

Thanks everyone, already taking steps you suggested.  I know many of you are going through the same situations with the resentment from a child that is not yours but you still care for and love.  The PAS and the other parent feeling guilty is a bad combo.  I just don't understand what parent would put their hate for the other parent over the love for a child. Breaks my heart for my SD even though her actions piss me off and hurts.