Animal Kingdom rewards a different plan than the other three Walt Disney World parks, and the reason is temperature. This is the hottest park on property, the one with the least shade on its main walkways, and the one with the shortest operating day. Everything worth doing outdoors - the safari, the animal trails, the walk through Pandora - is dramatically better before 11 AM and after 4 PM. Everything in the middle of the day should happen indoors if you can arrange it.
The second thing to understand is that the animal attractions have no queues. Gorilla Falls Exploration Trail, Maharajah Jungle Trek, the Discovery Island Trails and Conservation Station all have zero wait at any hour, which means guests who plan by wait time skip them entirely and then complain that this is a half-day park. It is a half-day park if you only ride the rides. It is a full and genuinely different day if you do not.
Third: this park has exactly three height requirements and two of them are 44 inches. If your child is under 44 inches, Avatar Flight of Passage and Expedition Everest are both out, and your day should be built around Kilimanjaro Safaris, Na'vi River Journey, the animal trails, the shows and The Boneyard - all of which are excellent and none of which measure anybody.