Does my music teacher hold something against me?

Well basically Im only thirteen and love music. I love to sing but I don't like been pushed to do it in front of people. This last two months I have met a group of sixteen year olds at my school , and one of my really good friends who is fifteen plays b in there band. I used to watch them everyday but now my music teacher wont let me even try to talk to them! And I play electric guitar and she wont let me practise at school no more. I can't play piano , but We were working on them last week and I figured out how to bit of black parade by mcr. I really dunno what to do. I askewd her if i could go in the music room at break to ''learn b'' and she said no to me but yes to my friend! this friend doesnt know my friends in the band she just wants to get to know them . Imean why would she let her in but not me , I havent done nothing wrong to her :(