He claims that she was. And he claims that she did “the same thing her bullies did”. But we don’t have any other details. Assuming good intent on the part of the administration (in this case, specifically the principal), I would guess that she was actually the instigator. I mean, it could also be that they were athletes or other stuff that can happen in a small district. But given the actions of her father and the observation that the nut doesn’t usually fall far from the tree, I’m guessing she’s the cause.