Rate rules for some rooms at hotels in Vancouver read Maximum Occupancy: 4 but, when I select 4 people per room, bookings show an "Extra adult charge (children may be exempted)" for 2 people. This never happened to me before at any Marriott hotel.

In my case the additional passengers are a 14 yo boy and a child. Questions are: Should I book 2 people per room to avoid having the surcharge already in my booking and show up with the kids? Should I book 4 people and negotiate at check-in time? At which age Marriott considers you an adult?