Stop at Guest Relations the first time you get into the park and get a "It's my birthday" button for her - the CMs will personalize it with her name, and have her wear it the whole stay. Usually you'll get some kind of pixie dust here and there, but it's also REALLY nice just to have so many CMs and guests wishing her a happy birthday on her whole trip.
(My ODD and my birthdays are a week apart, so we usually end up at WDW - She wore her birthday button all week, I wore mine only on the actual day, but then wore an "I'm celebrating" button the rest of the time - we got birthday cupcakes at Crystal Palace (for breakfast, oy!) and a card signed by all the characters there; on Kali River Rapids they let us ride twice (and more if we wanted to) without going through the line; and various CMs gave my daughter little toys throughout our stay - glowing ice cubes, glowing Tinkerbell, all the little toy things they put in the specialty drinks, etc. She was beaming. As for me, it was surprisingly nice to hear so many people genuinely wishing me a happy birthday.)