Good points.
Keith, bless you for caring but be careful; a co-dependent relationship could develop real easily here. Do a little research on what this means. Even if you're familiar with the term the details are important.
She DOES have to want to quit, but will power isn't the way. She's an alcoholic, that is, an
addict. And she knows it, her talk of rehab shows that. She needs support and the best place for her to get it is Alcoholics Anonymous.
You being a musician (jus' sayin'

) probably know some recovering addicts: Alcoholics or other . If not, ask around; you'll be surprised. Get her to AA.
Again, God bless you for caring, and keep us posted.