Tj is right, you wont be able to stop her drinking, that decision has to come from inside, and speaking as an alky, I know that nagging doesnt work. However , if she decides she wants to stop, then you can do a lot to support that by not drinking in her company. You have done right by coming to SR.
You cant do worse than give her a link to the site, and tell her to mooch around. Many of us do know we have a problem, but do not know what to do about it - it is a major thing to admit to alcoholism and to come to terms with never drinking again.
Little steps may move her to that realisation
I wish you well.