Hi Michelle!
Thank you for bringing your question to the Disney Parks Moms Panel!
Yes! The transportation that runs on race mornings is for both runners and spectators. Your family can definitely use the monorail to get to the
Magic Kingdom. Main Street,U.S.A. is my favorite spectator viewing area. They can also hop back on the monorails to get to the finish area at
Epcot if they want to do that after leaving the Magic Kingdom.
A few weeks prior to the race weekend, there will be an Official Event Guide that will have lots of great information for spectators. You should receive an email with a link to it, there will be a link on the
Princess Half Marathon website and it will also be available in print form at the expo.
I hope this helps! Please let me know if you have any other questions.