Hi Jaime!
Thank you for visiting the Moms Panel!
I think Typhoon Lagoon would be your best choice, with plenty to entertain your four-year-old.
She may love the huge surf pool, the variety of the water slides and Castaway Creek, the 2100 foot circular river where you can float along through a rainforest, and caves and grottos.
There is also plenty of enjoyment to be had at this water park, especially for younger children. Ketchakiddee Creek has everything for little ones to enjoy - slides, fountains, waterfalls, mini-rapids and much more, all in a safe environment.
Full details of all the attractions at Typhoon Lagoon can be found
here.
If you have any other questions, please come back and ask me - I would be happy to help you plan your magical vacation!