Shes just WRONG, Get rid of her or let her stay? its LONG Options

[Annie5332]

Alright so me and my group of friends are friends with this girl (We'll call her Zenon). Zenon transfered from her old school to our new school about a year ago, and nobody really knows why. We think its because she didnt have any friends there. So anyways, Zenon eventually started hanging out with the "cool" girls first, but got into a big fight with them that ended their friendship. Zenon came to our group to hang out with us, but we thought she was just using us until some other people liked her.

Eventually, we became friends and we all liked her, up until the point where she stopped hanging out with us so it was just our normal group again. It was really nice not having her with us, at least thats what I think, because she was really annoying and obnoxious. Me and Zenon get in fights all the time, which is mostly because I dont want to be her friend AT ALL anymore. So when this year started, she came to us again, but only 2 people liked her (which was her boyfriend and one of my best friends). I really was hoping she wouldnt come back to us, but she did. The only reason I think she really hung out with us was because her boyfriend (we'll call him Leo) Leo hung out with us and they were going out. So around last November, the two broke up and they still both hung out with us. Zenon tried to hang out with the cooler girls again, but none of them like her, so she came running back to us. Then Zenon and Leo got back together and blah blah blah. Just about a week ago, Zenon told Leo that "she didnt want him hanging out with other girls (meaning me and my other girl friends)" and that really ticked him off. So the next day, Zenon broke up with Leo. After hearing what Zenon had said to Leo, I was appauled. (Do you think I have a reason to be or was I just over reacting?) I was so angry that I was just fed up with Zenon, and after all the other girls had heard what Zenon said, they got pissed. Now really the only girl that likes her is my best friend (we'll call her Phillipa who is in Ireland right now). I guess now that Leo and Zenon are friends again, which I really dont want to happen because I want Zenon OUT OF OUR GROUP. She has caused so much havoc and so many fights, that it just pisses me off. So now the question is, why cant she just go back to her old school and be friends with her old friends? She wants to be friends with me, but from whats happened in the past between me and her, I dont think thats ever going to happen.
1. Do you think that I have a right to be really mad at her?
2. Im not going to over react or anything, but ERGG! She makes me so mad.
3. What would you do?

Sorry for the long story Hard to sum it up.

[anniepiee]

If you have a problem with her actions, tell her. In the end if you cannot stand her, just hang out with a couple of people and form a new group

This seems.. really middle school.

I thought Zanon and Leo broke up because Leo got ticked off, and they're friends again?