Why is she actin mean for no reason?

She completley exagerates a situation and calls me a perv and when I asked her partner for an answer she was saying it to me so I asked if I could just read it and the girl I'm talkin about said no and covered her paper with her book. I said I wasn't even tlking to u and she said doesn't matter its my answers. Her partner noticed that I hav 2 swirls instead of one on the back of my head and then the girl I'm talkin about said its ugly.whenever I get up and I walk to my desk I hear her say my name and say sumthin about me to other kids but idk what she is saying to them but she makes it knoown to me she's tlkin about me. Today when I was talking to her friend and laughing with her and all she offered my friend one of her snacks and this other kid that sit behind her but not me. She's flirted with me b4 like put her feet on my chair so I can't sit and then when I sat on em she kept it touching my but and refused to move her feet. One time I asked her for a chip and she said no and then when her friend who is a boy walks in and she gives him like 4 nd then the whole bag at the end nd she even told him she didn't giv me any. She also pushed me randomly and didn't wait for my reaction