I don't know the law of this actual situation, but if you have a court date, im positive you can fight it and get it dismissed (or reduced, pending your history)
Proof is a VERY strong word in the legal world. Her word against yours means nothing if she has no proof; but the same applies to you as well. (example)--> if you got away fine but ended up busting one of their noses in the process, it sadly "is" their word against yours, and unless you present proof that it happened the way you said it did (i.e someone in the group/witness admits that you were jumped) you're looking at being at the mercy of the judge.
If it happened the way you say it did, I feel bad for ya man, and I hope it works out for ya.
Oh, and before I forget, you mention that you were walking home from school...Im not sure if its a state law, but here in VA, if you have not reached your house yet, you're still considered "at school." Watched quite a few folks get suspended for two weeks after fighting once they stepped off the bus. Strange how that is, but if it does apply to you, you may want to go to the school for help; assuming the people that tried to fight you attend the same school. If the school knows them as folks that tend to be on the trouble side of things, they could potentially help you if you need to go to court.
GL
