I would just give her time to vent. Sometimes friends just get upset because they feel like they're being neglected, and just need time to relax. Believe me, it's happened to me lots of times.
I've done that before, so heres what I did, I talked to her and I told her I was sorry, and I invited her over and we had a blast! But first you have to talk to her about it, otherwise you're going to get no where :)
Well, see, I've already done that, I have always ended up apologizing for every fight we have (Which is at LEAST 10 a year) cuz' I feel really bad, even though its not my fault. and its just really hard and confusing, oh well...
NO! but thats the problem, I don't realy want to be her friend anymore but then she makes me all guilty and UUGGG! One time I tried telling her that I thought we should spend some time away from each other in a note she tore it up cried and ran away :(