Hi Done, I'm sorry this has happened. It must be a real blow to you.
Now you've called her on it, there's no further role for you. You certainly don't have to show her support and compassion if that's not your inclination, and her telling you that sounds like BS from a distance. Nor do you have to argue with her about whether she has been drinking. You both know the truth.
You can control your actions though and make your own decisions.