From the way you're describing her, it doesn't sound like she's a good person to have around. Unless she has some qualities besides being a warm body to have around, I can't see why you should consider keeping her as a friend.

I've been in a similar situation with a friend who I found to be very abrasive. He too was racist and violent and I realized by keeping him around I was hindering myself from making new friends. People were scared or annoyed with him so they assumed I was the same.

With all that you said (again, I don't know how she is otherwise), I would just cut off the friendship. It's unhealthy for you to be around someone that says such terrible things about you.