Is she a true friend?

My best friend and I are having problems. First off, there was this boy who I used to sit next to sometimes at lunch. He would kinda joke around and put his arm around me. Well, I developed a crush but I still shot him down because he was older. The later my friend told me she liked him. She gave him her number and what-not but he never called. The she was telling me how they “go out”. Which they didn’t. The she moved on, but not completely, to his friend. She told me she goes out with him but when they pass eachother they don’t speak. I hate to have to think of my friend as a liar. Then there’s this girl who is like the slut of our grade who is supposed to be her friend but she was flirting with the boy my friend was supossed to moved on from. She was crying at lunch about it. Then they are like best-friends the next day.And she had someone else yell at the girl about it with all these people around. She doen’t sit with me and my other friend at lunch enless our other friend is there. And she can’t stick up for herself either. And I’m tired of doing it for her. Then she’s all like I’m distant lately when she’s the one avoiding me! Sorry this was so long, but do you think she’s a true friend?