How do I deal with this girl?

Ok so there's this girl and I'm Absolutely fed up with her. We used to be friends but then she stopped inviting me places. At first I was ok with it like can hang out with my other friends that's fine. She then continued to invite all my other friends places except me. I hate it. I'm constantly feeling left out. I have ideas of why she doesn't like me. Another girl who she clings to, clearly does not care for me. I can't say the same for her because I don't know hew all that well, but clearly she thinks she can judge me based off of the little to no things she knows about me. Anyways, this girl who I'm fed up with clearly wants to be more "popular". Which doesn't make all that sense because if anything I think I have more friends outside our "group" than she does. Me and my other friend are the only ones who can see right through her. Shes fake and acts differently around different people. She clings to certain people she wants to be closer with and basically copies their every move. She is just constantly leaving me and a few other people out. It really annoys me because I'm friends with them too and their always busy doing stuff with her. I don't know how to deal with her can someone help me?