Why would this girl do this?

she moved her like 3 weeks after school started she asked me all types of ques. i told her about all my make up and were i got my clothes . she came to school like on monday looking like me she even wore the same jeans i freaked out ! why would she do that i told her nit to do it again and we got in a fight . im very popular in my school and she wasnt when she moved her i mean she still isnt popular but it makes my mad . every one said oww u look better anyways but im still pissed and i got kicked out of school for beating her up wgat should i do y is she doing this?