Hi and welcome to planDisney, Linda!
First, happiest early birthday to your granddaughter! How amazing will that be for her to spend her birthday at
Walt Disney World Resort! What a way to celebrate!
I know how disappointing it can be when the theme park you desire to visit is booked for the timeframe you are looking to visit. There may be a chance if you have the
Park Hopper Option added to your theme park tickets. You do not have to have a reservation to visit a second theme park after 2:00 PM, but you will need to have a reservation for the first theme park for the day. For example, you make a reservation at
EPCOT but really want to visit
Disney's Hollywood Studios, but can't because you can't get a reservation. You will first visit EPCOT, and then, as long as Disney's Hollywood Studios is not closed due to capacity, you can visit Hollywood Studios after 2:00 PM. Please note you must visit the reserved theme park first, so even if you have experienced all that you can there, I recommend going in and grabbing a quick bite to eat or do some shopping and when the time comes, arrive at the next theme park after 2:00 PM.
We are here if you need us prior to your arrival. Sending lots of pixie dust your way!
I hope your granddaughter has the most magical birthday!
Raquel