Hi Ashley! I love surprises, and I think your plan for your daughter's 5th birthday is fantastic! She'll be so excited to spend her birthday at Walt Disney World! Unfortunately, the
Tomorrowland Terrace Fireworks Dessert Party is not included in the Disney Dining Plan. You'd need to pay out-of-pocket -the current prices are $21.99 for adults and $11.99 for children 3 - 9. Peak period pricing goes to $25.99 and $13.99, but I believe your dates would not be peak. These prices are of course, subject to change.
You may want to consider dining at
Cinderella's Royal Table. Seeing her favourite Disney Princesses might be just the icing on the cake for celebrating her birthday. She'll definitely get the royal treatment for being a Birthday Princess! Another good option is
The Crystal Palace for character dining with Winnie The Pooh and friends. I've heard they also acknowledge those guests who are celebrating their birthdays. Both of these restaurants accept the Disney Dining Plan.
Ashley, be sure to pick up a free Happy Birthday button for your daughter to wear during your entire vacation. Often, Cast Members will pay extra special attention to the wearer of these buttons. It can be picked up at any Walt Disney World Resort check-in desk, or at Guest Relations at any of the theme parks. And be sure to mention you're celebrating a birthday each time you check in for table service dining - many times they'll bring a cupcake or sing.
I'd be happy to help you with any other planning questions you may have, so don't hesitate to ask. Have a magical day!
Kristen