Hi Steve!
Yes, there is a waiting area for spectators at the finish line. There will be food and drink vendors there as well as some entertainment and benches to sit on. Do keep in mind that the weather on race morning is usually quite chilly, so they would want to dress warm.
The chEAR squad platinum package would allow them the use of the Race Retreat tent. This would be a great place for them if you can buy it. You would also need to buy a ticket for your babysitter. There are sofas, tables, chairs, TVs, Disney characters, restrooms, food, drinks, etc.--all inside a climate controlled tent. The runners that purchase the Race Retreat package have use of it until they exit, and then the chEAR squad patrons are allowed to come in. It's the perfect place to hang out until your runner finishes and it's a great place to meet up for runner and their fans.
You can find more information on the
runDisney Princess Half Marathon website. Please let me know if you have any other questions about your race.