My friend keeps copying me?

I'm 12 she's 10... Mom my says I'm her role model but not anymore.. She takes ALL my words and on facebook she is friends with all my friends!! She copies pictures and clothing, see she never EVEr wore Aero and now all of a sudden she does.. She takes all my poems\songs I write and turn them into hers!! I can't take it! I want to tell her I don't like it but I don't want to hurt her. by the way. I live in a duplex with her.. And last time I stood up for my self I got into troble