Disposable cameras (preferably underwater kind) Sun visor, one of those spray bottle fans (my son just HAD to have one) Autograph books and pens,favorite snacks/juice boxes, gold "coin" candy snorkle mask.......
Be sure to mention it to your TA and your head server. You'll get the standard cake (probably 2 of them) and a round of Happy Birthday in the dining room.
For DD's 13th birthday, I hit the local card outlet and got door decorations. She liked them, and the little girls on our floor loved em. I got up early on the day of her birthday and did the decorating so that she saw it when she went out. DCL has a package of birthday decorations (they put it up for you). I think it was $30 for the standard, $50 for the deluxe. Mine were about $10 at the outlet, but I put up myself.
There are packs of "Mickey gear" that you can order from the cruise line. The flyer will be with your docs. You could also consider a gift basket from Shirley. She's really good with Disney stuff in the baskets.
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