What to do about a girl who has her own problems- but makes them into mine?

You shouldn't have to friends with her. Let her be fat and stupid. In a year you won't even. Remember this. You're only a kid. This stuff will pass. Also tell your parents about this. Your teacher souldn't even be involved in this situation and that girls mom doesn't have the right to tak to you like that. Your parents need to stick up for you. I have a daghter your age and I wouldn't let someone talk to her like that.