Welcome to SR - we are here to support you through this extremely emotional and difficult time.
Everyone is different of course, and I hope your wife is different than my ex-husband, that is for sure. What was (and still is) so heartbreaking for us is that my ex has totalled a car, lost his wife (me) and has alienated his 17 yr old daughter all because he is in denial that his drinking is "the" problem. It's hard for me to believe that he can't see it when we've all been saying the same thing for 25 years. He blames everyone and everything else, but he still to this day denies he has a drinking problem. His own daughter, the light of his life, hasn't spoken to him in 6 months because she is DONE....and guess who he blames? Me! Of course!
My point is to not be surprised if even the pleading of your children is inadequate motivation for her to quit. Don't waste too much more time trying to make her better. Focus your energy on being the best dad in the world and protecting those girls from the chaos of alcoholism and addiction. Please get them to Alateen or in counseling if at all possible.
(((Hugs))) Let us know how you're doing.