We've eaten at CRT 3 times and she was there all 3 times. Our last visit was this past Dec. She was also at the breakfast in Norway at Epcot.
The 'usuals' at CRT seem to be Cindy, Sleeping Beauty, Snow White, Belle, and Mary Poppins. When we were there in Dec. Snow White was 'out' and we had Wendy Darling instead. That is your basic lineup with one of the main princesses being out occasionally and someone else there to replace her- I've read of Wendy Darling, Alladin, Jasmine, Peter Pan, etc.
You can ask a cast member in a park where and when a particular character will be- they will be able to find out and tell you. One year we found Sleeping Beauty ALL ALONE at the international gateway in Epcot- we spent at least 10 minutes with her- that was 2 years ago though.
Good luck and have a magical trip!