This situation has happened in my family. The friendship ended. It was one-sided and based on alcoholic complaints. I'm sorry that you may lose your friend, but the circle of destruction from this disease can be huge. Better not to be taken down that path. You can do nothing to change her behavior or his, for that matter. Be honest with her about how you are feeling. Make no judgements about her behavior. Perhaps when she is strong enough to detach from him, you two will renew your friendship. I'm sorry you have had to deal with the effects of alcoholism. Be strong.