Hi Laurie,
Thank you for visiting the Disney Parks Moms Panel! As a father of three children under the age of seven, let me offer you as much support as I am able for your desire to take your children on a Walt Disney World Resort vacation. Your kids are at great ages to visit Mickey and the Princesses. We've taken our children as infants, toddlers, and preschoolers and had wonderful experiences at each stage. My oldest son was two when he first went to Walt Disney World, and my other children were six-months-old and five-months-old, respectively on their first trips.
The Magic Kingdom is my favorite park in the Walt Disney World Resort to visit with my kids. I would suggest spending an entire day, or even two, visiting. With the recent expansion of New Fantsyland, Magic Kingdom Park has more to offer than ever before. Your daughter will love meeting Rapunzel and a visiting Princess at
Princess Fairytale Hall. Your son can travel through Hundred Acre Wood with Winnie the Pooh and friends on The Many Adventures of Winnie the Pooh. If he likes animals, the Jungle Cruise in Adventureland is a favorite among Guests, and Disney’s Animal Kingdom has more than 1,700 animals and six exciting lands to discover.
Casey Jr. Splash 'N' Soak Station in Storybook Circus is great space for your son to cool off. There are similar play areas at Disney's Hollywood Studios and Disney's Animal Kingdom.
Unfortunately, I am out of room here for my answer. If you, or your mom, have follow-up questions please feel free to send them my way. I'm happy to help encourage grandma that the kids are at good ages to visit Walt Disney World. Planning first visits are a personal favorite of mine.
Have a magical day,
Bob A.