I have this friend that I've known since about 1st grade. I never really talked to her until about 5th grade. I started to hangout with her with a bunch of my friends which I think now is a big mistake. She lies, she is evil, and the meanist person you will ever meet. She continually made fun of people because I would not stand up for myself and neither would my friends. Now in 9th grade everyone hates her, they talk behind her back, never invite her anywhere... so finally one Friday night when I was hanging out with my friends, she texts us asking why she isn't invited anywhere and what is she doing wrong. Well she asked for it; my friends and I told her about 5 stories about how she lies and is mean to us and then she told us to stop because she was crying. Akward much. She is trying to be nice to all of us now. I am nice back to her the few times a month I speak to her now because we have no classes together but I still have hate for what everything she has done in the past to me. Should I just let it go or keep up this wall?

Observe her behavior. Does she seem to be truly trying to change or does it just seem like a big act? If you really think she's trying to improve herself then give her the benefit of the doubt. But mind your Ps and Qs when in her presence, meaning be careful of what you say and do around her. Don't say anything in her presence that you don't want repeated, that sort of thing.