I’m afraid your principal doesn’t understand the situation. Did you talk to her about the bullying or about mom? Your principal should be able to help you with the bullying. Please speak to her again. Tell her EVERYTHING these girls say, even if you’re uncomfortable. Tell her she’s the only one that can help you with this and it’s a big responsibility. If she says anything along those lines again, ask her if she knows someone else that you could talk to…
Don’t give up. Keep going.
There’s no way this bullying is ok, or a girl’s thing, or a part of school, etc.. It’s not. It’s definitely not a healthy girl’s thing.
Try to show these girls that you’re stronger than them and that it doesn’t bother you when they bully you. This sometimes works like magic. Good luck.