I would tell your daughter to stay away from her. How old is she? When my daughter took dance when she was younger, some kids would say mean things about her, and whisper, so we told her to stay away from them, and as hard as this is, we encouraged her to pray for these kids. That was hard for her, but it was a good lesson. It taught our daughter to soften her heart toward them, to trust God and to watch and see what God was going to do in this situation. I would tell her, "ask the Lord what he is trying to teach you through this". The kids started to be nice shortly after that.
If God is for us, who can be against us? Rom. 8:31