We have been on 6 Disney cruises and have had 2 to 5 rooms all on one card.You can even set limits for each room if you wish so you can be notified if the bill is going too high. You can go to Guest Relations at any time and get a total for each room. At the end of the cruise each room will receive a statement of what they have used their crd for and total $. You will receive a copy of each rooms bills if the card is in your name. They will ask you how you want to handle this when you check in and get your room cards. No problem.
Have a great cruise,
mom x4,grandma x4