Hi Katherine,
Welcome to the Moms Panel! If you are guest at one of the Disney Vacation Club
deluxe villa resorts, then yes - you will have the option to charge meals, snacks and souvenirs to your room account. Each member of your party that is on your reservation will be issued their own Key to the World card, which acts as a room key and you can activate charging privileges on any or all of them. All charges will be applied to the credit card you leave on file during check-in.
If you are not staying at one of the Disney resorts, I suggest purchasing a
Disney Gift Card for your family members. These prepaid cards act like cash, and can be used at most locations throughout Walt Disney World. I suggest starting with small balances on the card, and reloading as you go - just in case one is lost or stolen. Be sure to keep your receipts and jot down the card numbers because if you report a lost or stolen card quickly, they have the remaining balance frozen and transferred to a new card.
Hope this helps - have a great trip!