Hi there, Brandi!
One of the best parts of Walt Disney World Resort vacation is that there is so much to do for Guests of all ages. I too have three kiddos with a pretty big age gap and I can tell you it's not only possible to plan a visit for everyone, but it's fun!
Your littlest one can ride with you on any of the rides which do not have a height requirement. My family adores enjoying "it's a small world," Peter Pan's Flight and Dumbo the Flying Elephant together, just to name a few. You'll find a whole list of attractions appropriate for everyone on the
Planning for Pre-School Kids & Little Ones page. On many of the bigger attractions you'll want to take advantage of
Rider Switch. With this incredibly handy service, one of the adults can take one of the older children, while the other two wait with the 1-year-old. After they enjoy the ride, you simply switch and use your Rider Switch Pass to access the attraction without having to enter the regular line again.
Enjoy your family vacation, Brandi, and please let us know if there is anything else we are able to assist you with.
Magical Wishes,
Lauren