My brother in-law is the same with my sister. She is an alcoholic and has been for years. He sets boundaries, makes her leave then has her back. He enables her by doing this so she has no boundaries to adhere to. They have a son and I hope he isn’t going to be affected by her behaviour in years to come. It is up to the alcoholic to want to stop and nothing we say or do will make her. I have had to give up.