I've seen this happen several times, the worst case was with a friend who was severely abused by her boyfriend. She's been with him since she was 15. I always tried to be there for her and we talked many many hours, but she was afraid to leave him. One time she did it and moved out in secret, but he found out her new adress and stalked her. One time, she was at my place and when she left, he was waiting outside, kidnapped her and locked her in his apartment for several days. I think he abused her in every possible way. It didn't take long and she was back with him again, and eventually I gave up talking into her.

To my very surprise, she was able to break up with him a while later, but she had huge problems after that and was unable to have a "normal" relationship. After that, she's been through many dramas before she finally met the guy who is now her husband. A nice man btw and very caring, and they have a child together. But life will always be more difficult for her than it is for others.

But to answer your question: From my experience all you can do for such a person is to be there for her, listen to her, talk to her and occasionally point out that it's an unhealthy relationship (you probably need to be careful here as she seems to have given up on other friendships for him in the past). Also, try to show her that there's also a life without him. Women often prefer a bad relationship instead of being alone, some of them have such a low self-esteem that they think they don't deserve any better than that.

Sadly, things often need to go very bad until abused people are able to make the decision and end up the relationship.

Kirsten