Hello, Andrea!
Your little princess is sure to have a wonderful birthday celebration at the Walt Disney World Resort! It's my family's favorite place to celebrate a special occasion or accomplishment, and I am sure you and your family will make many magical memories when you visit. I recommend purchasing tickets for Magic Kingdom Park. You mentioned in your question that you want to see a parade as part of your daughter's special day, and this theme park would be your best bet for catching a parade this December.
Magic Kingdom Park also has the largest selection of attractions that will suit your daughter's age and thrill level. When my daughter was 3 years old, her favorite attractions at Magic Kingdom Park were Enchanted Tales With Belle, Astro Orbiter, Buzz Lightyear's Space Ranger Spin, and The Many Adventures of Winnie the Pooh. Your daughter will likely have a few favorite attractions that she will ask to experience over and over again on your vacation, too. Make sure to look over this handy
preschool planning guide for a sample itinerary, attractions and tips for visiting the Walt Disney World Resort with your young Mouseketeer.
I hope you and your family have a wonderful first visit to the Walt Disney World Resort, Andrea! Please feel free to stop back by the Disney Parks Moms Panel if you have any additional questions. Wishing your daughter a very happy 3rd birthday!