Wow, Stacey! What an awesome Christmas family celebration you've got planned! You have got to be the coolest family member to be organizing such a magical trip that will likely be the most unforgettable Christmas celebration for your entire family.
Reservations and payments can surely be handled by each individual family within your large group. You can link your reservations together either by doing it online - or calling the
Disney Cruise Line Travel Desk, so that they can link your stateroom reservation to the other staterooms that will be occupied by your other family members. Once you have your Reservations linked, each family can also share their plans online and it makes it easy to coordinate just in case you want to plan more joint activities or port adventures.
Your dining in the main dining room rotations can be planned accordingly too, and you can be seated as a big party. You can have the flexibility of doing an organized family activity for everyone, or, if some of your family members choose to do things on their own, they're able to that also. If the adults want to plan an
Adult Exclusive Dinner, for example, each of you can link your reservations together. Since you are a big party, you will want to get your reservations in as soon as possible. It will be like having a private party in a big private room, dining with your family -- and I've seen how some families have enjoyed that. Not too long ago, we were that family walking into the ship with matching T-shirts!
What an awesome event you're planning! Let us know if you need additional information, and thanks again for stopping by the Moms Panel site!