You and I sound like we're in the same boat Anne! I also have children with many years between them. My oldest two love the thrill rides but my youngest two, well, not so much. Luckily, I'm married to a wonderful man who happily takes his turn sitting out with the youngsters while I enjoy some of the more wild rides with my older two. Not to worry though, there are plenty of attractions that are suitable for the entire family.
Here are just a few:
Pirates of the Caribbean @ Magic Kingdom
All of the Fantasyland rides @ Magic Kingdom
The Great Movie Ride @ Hollywood Studios
Toy Story Midway Mania @ Hollywood Studios
Living with the Land @ Epcot
Spaceship Earth @ Epcot
Kilimanjaro Safaris @ Animal Kingdom
and TriceraTop Spin @ Animal Kingdom
Of course there are plenty of shows scattered throughout the parks at Walt Disney World that will be fun for the whole family. Finding Nemo: The Musical and Mickey's PhilharMagic come to mind. The Voyage of the Little Mermaid and Beauty and The Beast are also great!
And for those times when your party will need to split up, be sure to check out my friend Michelle's
video on how to use the Rider Switch pass!