Hi Christie,
The
Candlelight Processional is beautiful and moving, somewhat similar to a church service, except it's outdoors in the middle of a theme park. The orchestra and choir perform traditional Christmas songs and the celebrity narrator reads the Christmas story.
If your daughter does well in church, she probably will be fine for the processional, which lasts almost an hour. There's lots to look at during the performance: the singers, the candles and other lighting, the musicians, the narrator and the sign language interpreters, who add a great deal of expression.
By doing the dining package, you will have guaranteed seating, so you won't need to stand in line for a long time to enter the America Gardens Theater. That should help minimize your daughter's potential for restlessness. And it sounds as if the admission to the VIP viewing area for IllumiNations -- which is even better with the additional Christmas fireworks on the end -- will be a plus for her.
I hope that's helpful and that you have a wonderful holiday visit to Walt Disney World with your family. Enjoy!
Wilma