Layla, not 4 hours ago we were at that very same show, (ran for 65mins). my 2 boys, a friend with a 4yo girl another with her 33mo & 8mo.
My 2.5yo sat on my lap, 4yo sat & watched as did 33mo. 4yo was up dancing in the aisle... fortunately she was next to it & we were in the 3rd row.
There were many children (all girls actually) downstairs (we were in the dress circle) dancing right in front of the stage, but guessing they were in the front section too.
We were eating Apples before it started, so not exactly messy, but in honesty it is fast paced & really preschool geared so I think she would find it hard not to be interested if she knows the characters... our biggest issue was the Fairies were the biggest item & we don't know them & Postman Pat & Fireman Sam were only on a short time (but then they did have mail/fires to attend to) but over all the boys really enjoyed it.
BTW Santa does come on at the end.