If you’re trying to raise a compassionate person who treats other people well, a nice talk about being nice to other people is not going to do anything but convince the kid she’s gotten away with her bad behavior.
The stuff middle school kids say is a thousand times worse than the worst things I hear adults utter even in the darkest rage. Kids of that age seem to have a unique imagination for language and its ability to cause misery.
I took to writing stories about vengeance, about stabbing my friends with whatever was near to hand; pencils in the classroom, sporks in the cafeteria, a ruler in the hallway while classes were changing. I walked around with vivid images in my head of tearing those girls' faces off.