Hi, Scott! A normal family vacation can be tough to plan, especially with children of different ages. I have three, ages 18, 9, and four, so I know it can be a challenge to find a place where everyone is happy.
I have never had a problem at Walt Disney World accommodating all three of my children. For the most part, much of the stuff my youngest wants to do is still appealing to my 18 year old. The classics, like Pirates of the Caribbean, the Haunted Mansion, and the Jungle Cruise are still family favorites. Then we have utilized the Child Swap pass so that we could do the bigger rides with the older kids. Some of the rides, like Mission: Space, have a children's play area just outside the exit of the ride, so there is something to do with the little one while the older ones are on the ride. We also have used the time that the big kids are waiting for rides like Expedition Everest to have either Mom or Dad take the little one to do something the older kids wouldn't be as thrilled to do.
If your schedule allows, I would let each of the older children pick a day to plan. Let them draw a theme park out of a hat, and then have them visit the website at
www.disneyworld.com to see what attractions are there. They can come up with a list of must do attractions, and then let them choose where to go for dinner or a nice lunch. My kids always enjoy the trips that they feel like they helped make magical!
I hope you have an incredible vacation!