"then send the miscreant to the disciplinary authorities"Who's to say this hadn't already been done in the past? Also, you end up with a, "he said, she said".
Take the photo as proof. Then, give her a ten-day suspension for mouthing off.
Out the window is a no-no.
I truly don't think anything is going to happen to this girl. Her parents will probably sue the shinola out of the school district after they treck it through criminal court.