Hi Elise!
You'll be happy to know that you can celebrate your birthday any and every day of your vacation - in fact, you're encouraged to do so!
Be sure you get your daughter a special, complimentary Birthday Celebration Button to wear, available at the Front Desk of your Disney Resort, or in Guest Relations near the entrance of any Disney Theme Park. She can wear this every day, all the time. This helps Disney Cast Members to recognize her and wish her a Happy Birthday whenever the opportunity arises.
Whenever you are dining in Disney, just make sure you tell your Host and Server that you are celebrating your daughter's birthday.
And finally, you may want to check out the following website for some spectacular ideas to celebrate this special event:
Customize Your Special Occasion.
I hope you all have an amazing time celebrating this special occasion at Walt Disney World!