Yeah I used to feel that way too, because my sister is the only person who knows what we went through in our childhood with our psycho dad but, over the years I have tried to help and she always relapses and does horrible things to me. The last time she stayed in my house she threatened my kid when she was drunk and that was it she has been cut out now. Im very protective and so my kids matter more to me then her. She has decided to be more like our dad instead of recover and that is her choice. But I had to choose to keep her away. I don't know how bad your sister is when she drinks but my sister is very sexual and violent.