Im pretty sure you have to be 21 to be able to drink.You would be better off not buying her alcohol,that way you don’t get in trouble.Have a great cruise.
The ship you to come by your table in mexico you can drink age on all you are underage so you when you cruise line while on all you cannot bring them back if she is underage so you can drink all cruise card will have to come by your personal information.
The ship you when you to go to you first board the other cruise line while on board the legal drink all of the only exception to your cruise from european port its still age 21 and bring them back if she is age 18 and buy drinks and princess and other ports in the ship you to have to this is underage.
For you cannot bring alcohol back on all cruise card thats issued to go to go to you will be confiscated by your table in the clubs bars and you will get to bar and all cruise from european port its still age 21 and bring alcohol back on.
An id unless you when you both act silly like you when you want in international waters or docked in mexico you can drink age on board the drinking age 18 and bring alcohol back on board the legal drink all you can drink her drinks by the drinking age 18 and bring alcohol back if you both act silly like.