Hi Brenda,
I remember that commercial! That was really funny how her family was staring in disbelief as she was presented with the neon green flip flop.
(Quick Sidebar: My favorite commercial is the one with the little boy who was "too excited to sleep" on the eve of his family's Disney vacation!)
Back to your question...I absolutely love that idea!
The good news is that I happen to know who can help you pull off a special surprise. They're the Dream Makers in the
Disney Floral & Gifts department and they have a whole host of princess-themed surprises (including glass slippers and tiaras) that your birthday girl will absolutely love.
Here's a little tip from your buddy Derek:
While the Disney Floral & Gifts website (linked above) is awesome, sometimes it's worth giving them a call if you want to explore some options that may not be featured on the website (e.g. special deliveries to one of the restaurants in Walt Disney World, your resort hotel room, etc.). Their telephone number is: (407) 939-4438, so feel free to give them a call if you'd like to do some brainstorming.
I hope that helps! Please feel free to write back if you should have any additional questions and I'll be happy to help in any way that I can.
Best regards,
Derek