Physical & Emotional Abuse Support Group
Abuse is a general term for the treatment of someone that causes some kind of harm (to the abused person, to the abusers themselves, or to someone else) that is unlawful or wrongful. No one deserves abuse, period. Abuse can be emotional, physical, or sexual.
Other than that, your sister needs to sit down and sort out her priorities. From what you have been able to tell us we all feel that your sister is being abused. The issue now is how to get her to do something about it. Considering everything you have said and shared up to this point we all know how much you love her and care for her. But until she wants to actually do something about her situation it isn't going to change. And just so you know, by "do something" i mean leave him. The counseling and the intervention programs have a breathtakingly low rate of positive outcomes.
Have you considered getting *her* on this board?