Hi Tina:
I'm a parent of two boys, ages 5 and 4, and we always enjoy all of the Theme Parks at Walt Disney World. I would love to share some of my family's must-dos for our Disney World vacations. Your family may have different tastes, but hopefully these recommendations will be a good start to planning your trip.
For certain, I would take your family to Magic Kingdom. Among many other things, at the Magic Kingdom, we always ride the Jungle Cruise, Peter Pan's Flight, Mickey's PhilharMagic, and it's a small world. At Epcot, we take in Spaceship Earth, Living with the Land, and tour the countries of World Showcase. Our must-dos at Hollywood Studios include Toy Story Mania, Star Tours and Muppet Vision 3-D. At Animal Kingdom, our family always rides the Kilimanjaro Safari and visits The Boneyard and Conservation Station.
Of course, every family is different, and to have a successful trip, you will have to take your grandchildren's likes, dislikes, and comfort-level into account. As you enter the parks, pick up a Times Guide for parades and show schedules throughout the day.
You may also enjoy trying to take in
Mickey's Not-So-Scary Halloween party one evening. This separate-ticket event is a must-do for my kids every fall-visit. I would also try to plan a character meal, maybe at Chef Mickey's or
The Cyrstal Palace.
Also, I recommend having a look at Disney's
in-depth planning page for traveling to Walt Disney World with younger children.
Enjoy your vacation.