Welcome to the Disney Parks Moms Panel, Eileen! It sounds like your family will be in the Orlando area soon and you'd like to include one day to visit the place where dreams come true: Walt Disney World! That's so exciting! I'm so happy that you'll be able to take the time to spend a magical day at Magic Kingdom. That is the true Disney experience there!
If you purchase a
single park ticket for Magic Kingdom for one day, you are welcome to leave the park for part of the day and return later on to the same park, yes. My family and I do this all the time. We may be at the park when it opens and enjoy some attractions and then head on the
monorail over to a lunch reservation at one of the resorts nearby before popping back over to
Magic Kingdom to wrap up our day. When our kiddos were smaller, we'd have to leave halfway through the day to take them back to our resort for a nap and then bring them back later that evening for dinner, more attractions, and the nightly fireworks show.
If you choose the Park Hopper option, you are able to visit more than one park on the same day, so that is something to consider too, if you're interested in more than just the Magic Kingdom.
Have fun planning this magical adventure, Eileen!
Marcy