Well although the hotel's own website says they have Queen rooms and Double Doubles, hotel.com would only quote for either a King room or a Double. I elected to go for the double - and ensured that the reservation stated clearly that there would be 2 adults and 1 child. I also added as a 'special request' that we have a room with 2 double beds.
As for DS being a 'child' - we are going to New York for 5 nights to celebrate his 18th birthday. He will be 18 on the day that we check out! Pushing it a bit, I know - but according to hotels.com - they consider anyone a child up to the age of 18.
Fingers crossed we'll be OK!
Julie