That is horrible what his own mother did to him
This is indeed a sticky situation, I had forgotten that your daughter had an illness
So kicking them out probably would be a BAD idea, huh
? I know that you are hesitant to rock the boat because of the fear of your daughter having a relapse. I bet that she also knows this, and don't believe for a minute that she won't use that to get away with stuff. Don't be afraid to call her on this if you think for a minute that she's manipulating you. I had a close friend in HS who had problems and she used to laugh behind her parents' backs because she knew she could get away with anything or get anything she wanted if she acted like she was relapsing. Not saying that this is what your daughter is doing or will do, just wanted you to be aware of it if her therapist hasn't mentioned it.
I think you and your hubby are gonna have to sit them down and make up a contract that you'll ALL sign with what is expected out of them, and you.
If they want you to respect their privacy, then they must respect your home and your rules. They must behave as adults if they wish to be treated as such. It's worth a try, anyway!
Maybe you could even offer them a small discount off their "rent" for every week that they comply with the contract, and a small penalty for breaking the rules. You and Dh must discuss this in private at first so that you can be in total agreement before you talk to them. Type up the contract and make four copies, one for each of you, and have everyone sign each one.
Oh, I am sending you the biggest hugs because I know that you are in such a hard spot with this
I wish there was something I could do to help you! I sure as heck wished there was someone that could've helped me when my kids were raking me over the coals