Hi Lorraine!
I'm so excited to hear that you'll be headed to Walt Disney World soon! We loved touring the parks with our little ones, and Walt Disney World makes the vacation a family experience by making most rides accessible to kids of all ages! Only a handful (or so) of rides or attractions in each park will have a height requirement, so your little ones will be able to join in the fun!
For those rides and attractions that do have height requirements, Walt Disney World has the
Rider Switch option that will allow the party to split, and some stay with the little ones, while other members of the party ride, and later switch with the waiting family member. This will provide a reduced wait time for the second party experiencing the attraction, which is a wonderful bonus! Just talk with the Cast Member at the beginning of the attraction queue, and they'll give your your special pass for the attraction.
You can read more about Rider Switch at the link I've provided above. Between our 3 children, and multiple visits to Walt Disney World, I can tell you that my husband and I have utilized the option many, many times.
Have a magical vacation!
Amanda