Help with problem girl, girls only preferrably?

I'm 25, she's 24. We liked each other at first, but she's very flaky and we started bickering about that. Since this we bicker all the time, not heavy arguments, just bickering. She told me she couldn't date me since we're always bickering, but maybe in the future, but she keeps telling everyone she wants to sleep with me. Although we bicker she has always goes out with us. We went to a dance club one night and I left early and another female friend of mine told me she eyed me down on my way out and just blurted out "I haven't slept with him yet." She told her ,"Um, ok? Are you planning on it." She said, "Oh, well... I don't know." A lot of my friends who are her friends are girls and they always tell her she doesn't deserve me because of how she treats me. She told me a while back she didn't like to sleep around and wanted only to sleep with boyfriends, so it confuses me that she wants to sleep with me. What is going on?