Hello Cassandra! Welcome to the Disney Parks Moms Panel! I think celebrating your daughter's birthday at Cinderella's Royal Table will be a very special way to mark the occasion! It is very important that you make the reservation exactly at 6am EST on the 180 day mark for your
arrival day at Walt Disney World! You can then make reservations for up to 10 days after that, so if your daughter's birthday is during that time, you can actually make it earlier than the 180 days, as they count your arrival day as the marker.
The best way for you to make these advance reservations is online at
Disney Dining Reservations. I've included the link to make things easier for you!
I hope this information helps you with getting that magical reservation at Cinderella's Royal Table! Good luck, and please let me know if I can answer any other questions you have!
Have a magical day Cassandra!
Kristen