Why isn't Raven with the Cheetah girls?

A fan of the cheetah girls I am not, but I love Raven (she is such a good role model for girls everywhere!). So, I was wondering what's the deal with her and CG. I know she was in a cd with them and the first two CG movies, but there have been cheetah girl performances and a tour and a new movie, but I have not seen Raven. What happened?