Violence against women

Do you know anyone who is being physically or emotionally abused?  I know someone who is abused by her husband.  She has three children, so she doesn't leave him.  Everytime they fight, and I mean he beats her up, he doesn't go to work because he is afraid that she will leave him and take the kids.  I need some advice, because her husband is my brother.  I don't know how to handle the situation.  I was part of an abusive relationship, but I left my husband while I was pregnant.  I didn't want him to hurt our son.  I try to explain to her that it would be best, but the children are already 9,7, & 5, and they won't understand.