text: My responce to girls who did this to me when I was younger was to make sure I was the better person.  I might say a thing or two to a friend standing next to me, like the girl wasn't there, "Gosh have you ever seen anyone so DESPARATE to prove how jealous they are of me?  I must be better then them if they are that jealous!" and walk away.  Do not look at her, do not confront her.  Just say it close enough she can hear it and walk away.  I also found it best to not let them get under my skin.  If someone you do not like is trying to make your life miserable, busy yourself with other things and NEVER let yourself be pulled into talking about them.  If you really would like to end this, try walking up to her, when none of her friends are around, and yours are, but out of their hearing distance and say something like "look, I know we have had some differences in the past, but I think we are more grown up now, maybe we should try and get along, since we seem to have things in common (mention friends, clothes, whatever you might have in common) so lets try and be friends instead.  What do you think?"  If she disses you, just say "well I tried to be friends with you, but if you don't wnat that at least I know I am the better person"  Walk away.  You'll know you tried to be the grownup, and she will always know she missed an opportunity to have a new friend, instead of an enemy who knows her for the petty, selfish girl she really is.