Hi Illeana! Welcome to the world of running!
You have a few options for your family. The first would be for them to hang out at the resort while you run. You may want them at the finish line to see you though. In this case, they can hang out at the resort until it's getting close to time for you to finish and then take the Disney buses (assuming you are staying at a host resort) to the finish area. When the race is about a week away, you will be given a link to sign people up for runner tracking. The tracking will send texts and/or emails to them when you cross certain points of the race (5K, 10K, 15K) and give them your estimated finishing time. This is a great tool for spectators. I didn't know about it in 2009 and my dad ended up at the finish line waiting for me for over two hours with my boys! Your starting time will depend on what corral you begin with, so it could be up to an hour after the race officially "starts" before you cross the starting line.
They don't need to be a part of the chEAR squad to be at the finish line or even to go to Magic Kingdom to watch you as you run up Main Street USA around mile 5. To go to the Magic Kingdom, they would need to take a monorail from Epcot to the Ticket and Transportation Center and then the other monorail to Magic Kingdom. This is not a difficult journey, but it may be a little stressful with four children.
You can find more information about spectators on the
Princess Half Marathon website, by clicking on the tab "SPECTATORS". Please let me know if you have any other questions!