We enjoy all of the world class theme parks in the Lake Buena Vista/Orlando area, but out of all of them, Sea World is our family's favorite park. It was my son's favorite park when he was three (the first time we visited Orlando). It is still his favorite park, and he is 14 now. The park has great amimal exhibits and shows: The Orca show (Believe), the dolphin show also diving and aerialists (Blue Horizons), a Sea Lion show (Clyde and Semour), a cute little animal show -- dogs and cats (Pet's Ahoy), and a circus type show (Allure). We think all of these are very entertaining. Your daughter will love Shamu's Happy Harbor - an absolutely incredible children's play area that has enough to do to keep even older elementary aged kids entertained. The Wild Artic animal exhibits start with a simulaton ride that is quite fun and then you go though artic animal exhibits - polar bears, beluga whales, etc. There are two good coasters that are well worth doing if you enjoy thrill rides. I'm guessing your daughter would be too young for these, though. Animal exhibits includes chances to touch and feed stingrays, dolphins, and sea lions. There are also penguin, manatee, and shark exhibits that are pretty neat. I think the park has just beautiful landscaping and is a great day for all ages. We are, however, huge marine mammal fans, so may be a little biased.
Shade is available in all three of the outdoor stadiums, and the Pets Ahoy and Allure shows are performed in indoor air conditioned theatres.