15 year-old in room across hall

[complawyer]

it's not a matter of capability, or maturity. the policy is ncl will not book a cabin for a minor, unless someone 21 or older is booked into that same cabin. it's just a matter of booking (as i understand it) ncl does not follow up on who's in a cabin. just book an adult into the cabin with your child. neither your husband nor you need to actually sleep there,

 

if there are only the 3 of you, watch out, you may get dinged for 1 1/2 x's the cabin cost as it will show you are the only one sailing  in the other cabin. i also believe that it  is the ncl policy not to allow 2 cabins to be booked under the same name. so either way, they have  you coming or going.

[BirdTravels]

1 hour ago, psuboater said:

It is against NCL's policy to have a minor in the room without an adult for the nightly assumption that they will eventually be sleeping together in the same room. This is to cover NCL's behind if something were to happen to the minor.

Actually it is more so that they have have someone legally, financially responsible for the damage caused to the room in the event that there is a "wild party" or someone that decides that "not my stuff" and wreaks the room.