Sam, I'm sorry you've had this dropped on you. You said she did admitted having a problem.
Mixing the drugs and alcohol have her in a twilight zone. No doubt, if she does sober up, she'll regret a lot of her behavior.
I kind of think that if my husband had timed it right, taken me by the hand on one of those mornings when I was sick and hung over - and kindly, without anger, asked me to go get help. And had taken me to the nearest detox or ER, I really think I'd have gone. It's hard to make that decision yourself when you're all messed up.
Please do not misunderstand that I think you need to fix her or you can fix her. She has to do that.
You are a good dad to put your daughter's best interests first.