I can share that I had originally told my husband that he needed to get a place of his own when his treatment had ended. My gut was telling me that we needed time apart. That I needed some space. His incessant talking, blaming, button pushing mixed with my complete confusion, worry, second guessing (all the things I'm sure you are feeling to) resulted in me back pedaling and allowing him to come home. Things became crazy in a way they were never crazy before. He was now desperate. He new things were very very precarious. My kids will have awful memories that they did not have before he left for treatment. There were long nights of him ranting, raving, crying, blaming, accusing, throwing things and tearing things up - endlessly - for hours and hours. that stuff did not happen before. He would not leave me alone despite the fact that I did not respond at all. His drinking *increased* - and he embraced treatment and said he learned a lot. He had his 30 day chip when he came home. He was unstable and told them all kinds of crap about me and things meant to get sympathy from his small children. It was awful and I regret it with every fiber of my being. It was not good for my kids. It was harmful to them. I wish I would have seen that then.
She must manage this situation on her own. It is the only way anything will be successful. You can not do it. My advice would be to hold firm on your decision to get space in your living situation and then let her figure out what she wants to do about her treatment. It has been my experience that any 'conditions' I have made are just ignored. Always.
Best of luck. This is a hard time of year. I have three messages on my phone this morning from my xah wanting to come stay with me a week for Christmas. My answer has to be no. He is active in his addiction and he has no where else to go. If he comes down here and spends one night much less a week it will a) create enormous amounts of stress and anxiety for me and the kids because he is unwell and b) he'll never leave. He has no where else to go. I'm gearing up to call him and it isn't easy but I know it is right. He has options, he just only wants one, for me to allow him to live with me while he drinks. He's still chasing that down and we've been apart for a year and divorced since January.
And then I will look at the heartbreak and anger in my kids' eyes when they find out he won't be here. They do not understand now but I know it is best and so I will do it, just like I know it is best to do other things they don't like or understand and I do it anyway. I have to let go of the outcome and trust that the next right thing is all I need to focus on.