Hi Michele! Welcome back to the Disney Parks Moms Panel!
Your Walt Disney World Resort vacation is about to begin! All the hard work you have put into planning will pay off very soon. I know you will have a blast!
In my experience, there is usually a grace period of 15 minutes for dining reservations, but you might end up waiting for a table if the restaurant is busy and
50's Prime Time Café usually is. If you show up too late, the credit card that was used to make the reservation will be charged a fee for late cancellation/no-show. Trust me, this restaurant is a lot of fun and really tasty ... you want to make your reservation on time if possible!
While you are visiting
Disney's Hollywood Studios, make sure to allow some time for exploring
Star Wars: Galaxy's Edge. I was able spend some time on Batuu a couple of weeks ago and I was blown away by the attention to detail there!
Enjoy your vacation, Michele! Please let us know if you have any other questions.
Tabitha