Another suggestion: our oldest was "Mr. Picky" for eons, so rather than have him starve wherever we went, we packed him some food to take along everywhere. Disney CMs are so great about things like this. We always made sure to order plenty of food for the rest of our group so that the restaurant, CS or TS, made a decent profit and the CM made a good tip. Then we asked for an empty plate for oldest. He was allowed to pick off our plates if anything interested him (rare, but sometimes fruit was acceptable). I always packed him grilled cheese sandwiches or peanut butter, goldfish crackers, rice crackers, etc. Things had to be on the "right" bread, with the "right" cheese, cut into the "right" shapes, the "right" brand... you get the picture. As long as I knew that he had plenty of water, his multivitamin, and something to eat at every meal, we were good. And he knew that he had to behave at the table -- no fits or whining or refusing to eat anything. (And I will always be grateful to the CMs who managed to charm him into trying a bite or two of new things!) If your niece can find a few things that she likes that can be brought into the parks each day (e.g. protein bars, instant oatmeal, cereal packs, the mac'n'cheese packs mentioned above, sandwiches, etc. -- it doesn't have to be meal specific -- cereal for dinner is still a meal), it will get her through your trip and relieve the stress for her and everyone else.