To avoid disappointment (we actually have 7 children travelling) we signed a waiver form - which will be presented on boarding
That is interesting given the Royal Caribbean UK and Ireland website says no waivers will be accepted for the age limits. Did the cruise line tell you it was going to allow it?
An excerpt from the booking conditions:
The minimum age for infants to sail is six (6) months, as of the date of sailing and twelve
(12) months, as of the date of sailing for Transatlantic, Transpacific, Hawaii, selected South American cruises and other selected cruises. The health and safety of our guests is our number one priority. As such, in consideration of the limitations of the shipboard medical facility, equipment and staff, the company can not accept waivers, releases or requests for exceptions to this policy.