Hi Michele! I recently celebrated my daughter's Sweet 16 at Walt Disney World and it was a birthday she will never forget! I'm not sure if it's in your budget but she brought a few friends and we stayed at the new Art of Animation resort. I got the bedroom and the girls had the rest of the suite to themselves. It was so much fun to listen to them sing themselves to sleep after a great day in the parks and having her friends there made the fun happen with no effort!
One thing that is a must is to get a birthday button. The cast member wrote "Sweet 16" on her button which drew extra attention. For fun, the girls counted the "Happy Birthdays" my daughter received and they stopped counting at 100! We also arranged for dinner at one of her favorite restaurants (Garden Grill - she loves Chip and Dale!) and ordered a Chip and Dale themed birthday cake by calling the Cake Hotline (407-827-2253) a week before our trip.
Another idea is to arrange for a tour. Two that come to mind are the
Wilderness Back Trail Adventure (minimum age is 16) and
Wild Africa Trek. Both are experiences she will remember.
I also decorated our room with "Sweet 16" decorations which I brought from home. You can also contact Disney Florist for delivery ideas. If an in-room celebration is in your budget, that would certainly bring a "wow" factor!
I hope this gives you a few ideas. You can find more
birthday celebration ideas on Disney's website. I hope your daughter's birthday is truly magical!