Hi Margaret,
I love traveling to Walt Disney World with large groups! Our family of 18 goes together at least once every year or two, and it's a fun & crazy time full of great memories.
And, a great way to capture those memories forever is with
Disney's PhotoPass Service.
For the Character Dining, you can either purchase the PhotoPass + , or you can add the Character Dining PhotoPass Package on to your PhotoPass card at the restaurant. However, after doing the latter a couple of times, it makes more sense to purchase the PhotoPass +.
PhotoPass sharing is possible. One of the families would need to purchase the PhotoPass CD, have all of the PhotoPasses linked to the one CD, and then be responsible for having copies made for the rest.
I hope this is helpful. Have a blast capturing those magical memories!