I am travelling with my wife and 2 year old in F on 777-200. Are children allowed in the A or K seats? I am able to move me or my wife into them but not my 2yo. We were going to keep the seats we have and switch on the plane, but if the FA wont allow it we have to change out seating plan. Perhaps it has to do with the rare case of O2 mask need?Many thanks.