Hi Brenda! Your daughter will be a lucky girl to be able to celebrate her birthday at Walt Disney World!
You did not mention the age of your daughter so I will suggest you have her choose the theme park that she would most want to spend her actual birthday at. For this one special day she will be allowed into that park for free. You will have to make sure you have proof of her birthday through a drivers license, birth certificate or passport and present that to Guest Services at the entrance to the park.
Younger children tend to gravitate to the Magic Kingdom as there are many rides and attractions for them to enjoy. If you are only choosing one park to visit then I would suggest it be the Magic Kingdom since that is what Walt Disney World grew up around. The magic of the castle and everything else can't be duplicated!
The other three parks are just as awesome and if you have the opportunity I would hope you would also visit them for a day. From the Swan you can walk to both EPCOT and Hollywood Studios which makes them very convenient to your location. For that special animal treat the Animal Kingdom park is unbelievable and full of many opportunities to be up close and personal with animals. Please click
HERE to see more descriptions of each park and the attractions that they have. I say visit all of them!