WOW - 7 year old alone...Let's keep her fingers crossed she gets seated next to a Mom or Dad...who will likely help her out.
Some ideas I would do:
- Keep her carry-on VERY simple and basic and light. A backpack from school that will fit easily under seat in front of her (make sure she doesn't get first row seating - no underseat storage).
-LOTS of snacks - anything dry can be brought - goldfish, cookies, M&M's
- can you walk her right to the gate? I think you can even without boarding pass for 'special' travelers which solo young kids qualify (you might need to call airline ahead to arrange this) - if so, buy her a bottle of water AFTER security and put it in the 'holder' on the side of the backpack. Tell her to use it if her ears hurt on the way up or down (have her get it out of the backpack as she sits and put it in the pocket on the back of the seat in front of her as she won't be able to get the bag out during takeoff or landing).
- BOOKS are the best activity I can think of. Buy a bunch of new ones at her reading level and put them in there as a surprise.
-Activity book like a word search with a few pencils in the backpack pocket just in case one drops.
-a stuffed animal or doll that is familiar from home - she might be missing family on the flight- this way she'll have a 'loved one'
-How about a magnetic book - you can buy one at
Walmart - take apart (at home, before) the different magnetic characters and put them in the 'book' - different scenes to make up different stories.
That's probably about all I'd do. Don't want her to have too much to keep track of.
Good luck.