Personally I think that staying in an abusive relationship is detrimental to both the mother as well as the kids.
An abuser believes that the person he abused was at fault, therefore his actions are justified to himself. If a person believes that they are right and justified in their actions, are they likely to change?
Women stay in abusive relationships for many reasons, sometimes its becoz they have nowhere else to go, other times its because they love their husbands and believe that things will change. And sometimes they do it because they think its better for their children.
I agree with that 100%, parents are supposed to be role models for their children. By staying with an abusive partner, the odds are that the son's will take after their father and become abusive in some way or other to their wives. And as for daughters, they'll develop self esteem issues, and will grow up thinking that its all right for women to be treated in that way. Also realistically speaking, an abused person will always be unhappy. It follows that the children seeing their mother unhappy will also be miserable and unhappy.
Again i agree 100%. By being abused a women will lose any self respect or dignity she may have, her self esteem will drop tremendously, she will live in fear of when the next beating is coming. Living this way for many years may eventually lead to having a nervous breakdown.
So i would advise anyone in an abusive relationship to leave. I'm not saying that people can't change, by Allah's will its very possible that they can, but in most cases they very rarely do.