Hi Katie,
Welcome to the Disney Parks Moms Panel! I tip my hat to you for taking on the monumental task of trip planner for a large group!
You can make
advanced dining reservations for a group that size online or using the
My Disney Experience Mobile App. The larger the group is, however, you may have to call and speak to a cast member in dining at 407-939-1947 to find seating for the group. On a recent group trip, I had to call to make two dining reservations for 14 each to secure seating for our entire party. The reservation times were 5-10 minutes apart but the cast members at the restaurant graciously seated us together.
Pay careful attention to the cancellation policy! On one trip, I failed to cancel a reservation and was charged $10 per person. Lesson learned. I now pay close attention to the dining reservation reminders I receive via email so that I can cancel if needed. Also, remember to ask about food allergies in your party. Make a note of those when you make the dining reservations, or call and ask a cast member to notate it on your dining reservations. Everyone in my family has some sort of food allergy, so a chef typically comes to speak with us at table-service restaurants to make sure we are clear about what we can eat at the restaurant.
Katie, I am sending you extra pixie dust loaded with patience as you plan this trip of a lifetime!
Magic, memories and Minnie Mouse hugs,
Donyell