4 Year old physically abusing Great Grandmother

[gshnwilson]

My 4 year old daughter has gone though a lot in her life (unfortunelty) her father and I do are best to get along but...It never works....His Grandmother raised him (her Father) and from the time of meeting him i seen he treats his grandmother like dirt! never has he talked to her respectfully and I know my daughter has witnesses this behavior but it has been a almost 2 years since he has talked to her like that.... so last time she had to see this was when she was two.....This GREAT grandmother of hers is married to a state procesutor in the state i reside in and when thier father and her were not getting along she took me to court and the gave her bascially a parents visitation with my childern that is everyother weekend from friday at 6 till sunday at 6. Since this court order was placed it was ok for the first few visits then my daughter started calling her grandmother names and threating her for example... I called to check on them i heard my daughter yelling at her in the back ground saying " if you don't get off that phone I am going to hit you" i was thrown when i found out this behavior was going on because she does not act like that towards any one or at any other place (ex. daycare, home, her maternal grandparents, ect) Just at this grandmothers and just to Her..... Well their father and I split up with in the past few weeks and he moved back in with his grandmother...(her great grandma) and since this my daughter has been physically abusive to her great grandmother and i mean kicking her so much it busted her knee open.... Just last night when they were over for a visit she lashed out at my son (her 100% biolgical brother, who is 2) it was told to me that my daughter and my son were sitting on the bed and out of no where she punched him in his cheek, knocking him over and when he fell over she started hitting him and kicking him and the grandmother could not grab her off him she had to result in pushing my daughter of my son hurting my daughter in the process of protecting my son..... MY daughter has NEVER EVER acted this way towards him the normal sibling thats my toy arguement and thats all..... I just don't understand what is going on with her I have talked and talk and talked to her and it gets NO where! All I get when i ask her "why are you mean to grandma?" she always answers "because, I don't like her" but she never tells me why she doesn't like her.... But like i said the thing that just blows my mind is this is the only place she has problems and Grandma is the only only she is abusive to (other than this one time to her brother) I don't desplay this type of behavior in my home, neither does their dad so where she is seeing his behavior is beyond me..... What can i do, where should i turn? it hurts me that my four year old is behaving like this