Your request is neither abnormal nor unreasonable.  I can sympathise as I have an SD25 suffering from failure to launch also.  I don't get the worst of it as she lives with NPD BM - I would not permit her to live with us, and feel no sense of apology about this.  If I were you I would stick to what you and DH said to SD20, and if she is not in college in the autumn, then she needs to be working full time.  Sadly, this generation of precious little snowflakes seem to think that their parents will be happy to have them freeload forever, squatting in their parents' houses like giant cuckoos, beak ever open. 

I think it is totally normal and reasonable for a 20 year old to work full time if she's not in school. If she's in school part-time, it might be reasonable for her to work a little less than full time if necessary to accommodate her school schedule (you do want her to finish her transfer requirements and get out of your house, right?). When I say a little less, I'm talking 30-35 hours vs. 40, not some 10-20 hour job.

Why did she fail 2 classes? Lack of effort or lack of ability? If it's lack of effort or some deliberate sabotage, she should be given a deadline to go to state school or move out, and the deadline should be no more than one more semester.  Can she finish her 2 classes over the summer?

Well, what else would she be doing if she's not in school and not working? Does she think laying around doing nothing is an option?

 I thought she missed her Mom so much and was only there for college opportunities? I'd say if she's not in college she has to return to her mother's.  

Laying around all day doing nothing ?  Yes, she needs a full time job, and you must set up a saving account where she saves money. For a down payment on a apartment, furniture, ect.   Make sure she can not take money out of that saving account.  Thanking money out is not saving 

If she refuses to work them maker her your house slave.  Make her do everything a maid , cook and landscaper would do. Make her miserable so she's motivated to grow up , find a job, take classes or move back to mommy's.   Lots of fights in your future until she gets it or gets out.   No treats or gifts for her either.  Don't let DH treat her stuff on the sly. She needs to be miserable. I had a "paralyzed "18 yo after graduation. I laid the law down when I figured out what was going on ( she was my first to go thrubthis) and she was in college  classes next semester and had a job.  I didn't make the same mistake with my next two.  Expectations can and willl be met.  Coddling is the worst thing for this affliction. 

Parents fault.

You/dh have is wrong. IF she is not in school full time she is OUT on her own, in her own place. Paying her own rent, paying for her food, her car her phone, her insurance ....everything.

About bm wants her back...ok. Let me ask, did DH have full custody and bm eow when she was a minor?

Full time school OR out in her place. She would be smart to get a 2, 3 bedroom and room with friends.

If she goes to school,,,summers are working. SPRING BREAK goof off,,,sure if she can pay for it.

She picks.

What REALLY stood out to me was that she feels 'intimidated' because you work at FT 40 hour job!!!  WTF?!!  If this wasn't a joke, was she trying to put the blame on you because she has no motivation?  There are several SM's who would not give her the opportunities you are so generously providing for her.

I agree with Surviving - make her a house slave.  it might make BM's house look a lot better.

Op did Bm have residential custody OR did dh OR did they split with zero child support exchanged? Do you mind me asking?

Just curious, ok?

You and DH have nailed it with college flunky SD-20 having to work full time.  My SS could only reside in our home after turning 18 if he was working full time or a full time college student in good standing with his school.  He chose to do neither.

So......... we made him our life in beck-call-boy/chore bitch.  At bedtime every night we turned off the internet and the cable and it did not come back on until we returned from work the next day.  He had a massive spreadsheet chore list that he had to get done each day or the next day we left him on the curb when we left for work.

He swept, vacuumed, mopped, dusted, polished, cleaned scrubbed, touched up, weeded, edged, trimmed, watered, mowed, washed, folded, sliced, diced, chopped, cut, measured, cooked, served, cleaned and put it all away.

If we went out to dinner, he came with us. But.... being fed, housed, clothed and tolerated was totally dependent on his getting each days chore list completed.

We did not make it  contentious.  It just was.  After 4mos of working for only room and bord he figured out that he could get paid for working so decided to enlist in the USAF.  He went in on the delayed entry program so to keep living in our home he stayed on the get his chores done daily program until he reported to MEPS to ship out for BMT.   Next month will be his 9th service anniversary in the USAF. He has decided to make it a first career. 

So, if she is going to be in your home make it a one day at a time thing dependent on her working her ass off. For you. The more menial and misery inducing the better.

Good luck.

Absolutely she should at least get a 40/hr/wk job and pay rent which should include utilities.  She should also help clean, etc.  If she doesn't agree to do those adult things, she should be told to find a place of her own.  Period.  

You are definitely not being unreasonable and your concerns are super valid. Why would she want to launch when it is safe and comfortable there?

My own DS tried this nonsense when he got out of high school. Almost didn't graduate. Didn't study for the SAT, then was shocked when his score was only average and a local university declined him entry. He went to the local community college and failed all three classes he registered for. He quit jobs willy nilly and in general just wanted to sit around the house playing video games. My DH (not his father) and I pushed him pretty hard to get off his duff and get a job, figure something out, etc. He would just be a mule and refuse to do anything, so one day, after warning him it would happen, we disconnected Internet access during the day while we were at work. He texted me that he was going to live with his dad and he left that very day. He has not lived with us since and it would take a LOT for us to let him move back in. He is still living with my ex-H to this day, two years later. He works full time now but still doesn't have a drivers license, a car etc. He has made progress in learning to save his money and should be able to buy a vehicle soon. It was strained between us for a while, but he has shaped up - and I have zero regrets for drawing that boundary. My Ex isn't much of an example to him and isn't helpful. Its painful to watch, but at least he isn't on the street, doing drugs or getting into trouble. Just a bit anxious about adulting and more than a little lazy. Its improving slowly. 

Ultimately our job as parents is to make sure they can live without us. Coddling them this way is the opposite of that. Ask your DH what will happen to her if he is killed in a car accident or has a heart attack or something. What will become of her? Because she sure as heck won't be living with you. Ask him how this fight will get any easier when she is 30. 35. 40. Because she will kick that can down the road as long as possible.