Daughter’s father is in a new relationship and his partner has children, one of whom is the same age as her. They share a room when she goes over. Last night she showed me some group chat messages where the step sibling and her friends had written vile things directed to my daughter. She was terribly upset about it. She’s told her dad who’s said he was sort it. Should I say something too? And how do I go about it without coming across as the bitter ex wife?