Mp: It isn't going to be easy for her to just STOP. She is doing her best, right?
She has a disease.
She admitted she has a problem finally. That is the first step in many "first steps" she will be taking.
Don't say "Nevermind" and be angry with her.
You say she has been drinking for so many years that her body depends on it. It may not be a matter of choice when she slips up.
Keep believing in her. Keep telling her you believe in her.