You dont. My dad does get abusive and he acknowledges he’s an alcoholic yet struggles to keep it away. We’ve tried supporting him to go to therapy and groups but it never works out. Now my siblings and I just stay out of it. If we see him drinking we instantly leave and get out of the situation. Who knows maybe someday he will realize how much we hate being around that and choose us over alcohol. Honestly I think the only way is to limit how much you are okay with them being in ur life. Hopefully some day she will realize your more important too, but then again I wouldn’t count on it, alcohol has a way of taking over. I wish u the best though, I know it’s a hard thing to deal with.