per the Disney website, it indicates that there are adult, jr and child rates. (So each should be charged accordingly, no matter if there is more than one room, however, the special also reads "price per adult with double occupancy." I would simply call of I was you and see what they say. Since it appears there are only 2 adults and one child, the infant is free, you wouldn't need another room (uness you feel you need it for privacy, but that is a huge savings to all be in one room at a value). Good luck! Let us know how you do!