Welcome to the DIS! Yes, your younger child has free admission for everything. Also, the child eats free at table service restaurants. At that age, your children will probably enjoy the Kilamanjaro Safari, the petting zoo in conservation station (Rafiki's Planet Watch train ride to the petting zoo). Tough to be a bug is quite intense and frightening to the younger set, my younger daughter, age 9 now, refused to do it until last year. Go figure. It's in the dark, 3D, and there are smells, sounds wind and misting water. The only 3D show I'd possibly recommend for those ages is the Muppet one at Disney MGM. MGM also has the Playhouse Disney show and BEauty and the Beast show. Animal Kingdom has the wonderful Lion King show that most kids enjoy. Of course Magic Kingdom is tykes wonderland. Enjoy your trip!