If It was about Cinderella for a 6yo I would not book CRT. Cindy is there in the lower lobby for pictures but she is not there at the meal. The Fairy Godmother and mice twirl around the room but don't even stop to talk to the little ones.
I know my 3yo would never understand that, heck, my 7yo would not understand either.
I would choose 1900PF as a 1credit meal because they characters really spend time with the kids and the food is not gross buffet food...
Or I would reschedule the castle for breakfast where the characters actually interact with the kids. It's hard to mess up breakfast food. It's my favorite meal of the day