You really should wait on dating. I think breaking up with her would be a good idea, but only if you can do it without hurting feelings, here's what I think would work out for you.
1. Tell her that you really don't want to get involved in a relationship right now and that it'd be ok maybe when you were both older and in high school or something. Be straightforward, and tell her exactly how you feel.
2. If you really can't like confront or do it face to face, write her a note explaining it all.
You can still be like the greatest of friends and there is nothing wrong with that, dating at this age just isn't sensible and has no purpose. It can only lead to creating desires that you shouldn't be having at that age. The purpose of dating is to find the qualities in people that you would find ideal to marry, and eventually you may stumble into that person that you want to marry in a date. Just wait it out, it's well worth it.
