Hey there, Tyler!
My two oldest daughters are 10 years apart, and that is one of the biggest reasons my family loves
Walt Disney World so much. There is truly something for everyone, and there are as many things to do all together as there are things to do with your older child individually.
The first thing I would do is go down the list of
Disney theme park attractions with your 10 year old and get a good feeling for the things he'd like to do. You may be surprised at how many of them his baby sister can do as well. Attractions like
Pirates of the Caribbean appeal across the board - they're fun for your big guy, but your little princess can tag along as well.
Absolutely use the
Rider Switch option, which will allow you to wait in line once, but you can switch adults for a second ride, which means your son will get to ride twice - once with you, while someone else waits with the baby, and then with the other grown up when you switch off.
You may also want to plan a special meal that your older child chooses, just so he feels like the vacation has something special for him included. My kids love
Whispering Canyon Cafe for the slapstick fun.
I hope you find your vacation with both children absolutely magical for everyone.
Anna