Hello Princess Catalina!
I have participated in the
Disney Princess Half Marathon Weekend for the last 5 years! It is my favorite weekend with my girlfriends, and runDisney really does put on the best races. Once you complete the Princess Half Marathon, you will finish in the Epcot parking lot.
If you want to use Disney transportation, then I suggest taking race transportation near the Family Reunion Area after the race to either
Disney's Grand Floridian Resort or
Disney's Contemporary Resort. There will be signs for each Walt Disney World Resort hotel. If you want to ride the monorail - the Highway in the Sky - one stop to Magic Kingdom Park, then take the bus to Disney's Grand Floridian Resort. If you want to walk to Magic Kingdom Park from Disney's Contemporary Resort, then take the bus there. Usually when I finish running a half marathon, I like to take a little rest and then need to keep my muscles moving. Luckily walking around the theme parks helps!
You could also walk to the monorail station at Epcot after the race and ride it to the Transportation and Ticket Center to go to Magic Kingdom, but it's a bit of a hike. However, that may be your best option depending on road closures and traffic.
I would budget 30-45 minutes to get there. It all depends on how quickly the transportation comes, and some roads will be closed due to the race.
I hope you have a wonderful breakfast, because you will certainly have earned it after running 13.1 magical miles! Have a great race!
Tania