So, after talking to the teacher myself, I decided not to punish progeny. She was defending herself the best way she knew how, and she had been punished by the teacher mildly for the violation of school rules. I did have a talk with her, and DW and I got her a treat to show her we weren't mad.
Short and skinny of it, I'm proud of her for standing up for herself. I just can't work up a proper mad. And I'm going to teach her how to fight. So that if anyone starts it, she can finish it.