Hi, we added an adult to our package last year about a month before we went. We had to pay 10.00 or 15.00 extra for her per night due to 4 adults in the room, plus the price of her package. But we didn't have any problem adding her. Just called our TA and she told us how much . We had to pay for everything when we added her because it was past the time everything was due. Everything else was already paid for. Her paperwork even arrived with ours. Hope this helps.