A recent experience from a friend.
If you add 1 kid to your booking with 2 adults, you can only select Grand rooms or bigger.
2 kids > Two bedroom Villas.
As he previously booked a 2 queen bed villa with points, he contacted the hotel and wanted to add the two kids <12y to the reservation.
He was told, that a King or 2Queen bed Villa cannot accomodate more than 2 people and would have to pay to upgrade to a Grand villa
Basically rollaway beds are complimentary, but you have to pay for an upgrade to put these beds in your room.