She doesn't respect you. I know what that's like. I have this "friend" who is a complete b*tch (Will you answer my question about her?
http://answers.yahoo.com/question/index;_ylt=Aq2Zx1KA1EYjN7kc.50kl5Lsy6IX;_ylv=3?qid=20081023173440AAHVK5H )
You have to get her to respect you more. You have to let her know it's not okay to make fun of you. The person I mentioned above is passive-aggressive. (Well, she used to be. Now since I've taken her crap she's just aggressive.) Your friend sounds passive-aggressive too.What you have to do with the passive-aggressive is make them feel uncomfortable with making fun of you. Give them a weird looks after they make fun of you, they'll probably rush to say "Just kidding." If giving them weird looks doesn't work, challenge them until they back down. Call her names if she insults you. She'll get sick of it and stop making fun of you.
Or she'll avoid you...but maybe that might be good for you. I had this other friend, (different from the one I mentioned above) who used to be my friend. Right before she started avoiding me, she started treating me like that. Now she hangs out with different people and is a different person. I'm okay with that. Our split was harsh, but now I don't get annoyed when I hear her name. She's just one of those people I don't talk to, and I'm glad. The person she is now is not someone I would want to hang out with.