My daughter took me aside to make a teary confession that she is violent and a bully. She is doing really well at school and isn't in trouble with the teachers.
On a near daily basis she gets into fist-fights with the boys in her friendship group. She assured me that she doesn't call names, never is violent with girls, and doesn't target one boy in particular. Because she's female, the boys don't fight back, so she hurts them more than they hurt her. She says she has gained a reputation for being violent and the boys try to goad her into lashing out.
She is strong and has always been more into rough-and-tumble than your stereotypical girl (never one to sit and colour, or play with dolls), and although violence not acceptable, I'm not sure what she has described is bullying. But she certainly feels terribly guilty that she is - and needs some tools to control herself. Any pointers would be appreciated.