S.A.
First of all, though your husband may think it is cute, he has to put his foot down and set her straight. I think I may have done a bit of that when I was little and my father had to sit me down on more than one occasion to explain that though he loved me very much mommy was his wife and he loved her very much. He would tell me that one day when I grew up I would get married and have a husband and children too....but I would not be allowed to hit mommy or yell at her every again. And he would punish me if I lashed out at her. Without his assistance in this matter, you will be hard pressed to correct her behavior. She needs to know that daddy loves her and he loves mommy and he will not let her be mean to mommy ever. His admonishment will go a long way to improving her behavior.