Have you considered rehab? I have even heard good things about AA.

Have you also tried to talk to her when she is reasonable? Do you know why she is doing this? Getting some basic answers might help

I am sorry that you are going through this, and I am always amazed to hear about people who have loved ones going through these types of things, but they still love them. It must be tough, even if you are family. Especially if you are family