If you do the early check-in, you can select the time when you expect to check in for the reservation. I would do that and select 8:00 AM. Hopefully that will increase your chances of a room being available when your daughter arrives. Of course, at AKL, I would expect chances to depend on what type of room you booked because I'm sure some types are more popular than others and may be booked solid back-to-back.