Hi Melissa,
Most of the large villas at the deluxe resorts are designed for up to 8 or 9 guests. You do have a few options, though.
Bay Lake Tower at the Contemporary Resort, Boardwalk and Saratoga Springs each have three-bedroom villas that can accommodate as many as 12 guests. Those villas cannot be reserved online. You would need to call the reservations line at 407-939-6244 to book.
The reservations cast member can also help you decide whether there might be other options, such as adjacent family suites, that would meet your needs.
Once you have your resort accommodations set, you will probably want to make
advanced dining reservations, too. With a party that large, you likely won't want to have every meal as a group, but for the ones you do want to share, the earlier you make the reservation, the better.
You can reserve seats at table service restaurants up to 180 days in advance of your trip. Make sure you note on the reservation if you are celebrating a birthday, anniversary, family reunion or other special occasion.
I hope that helps. It sounds like you are well on your way to planning a great time together.