To make sure you have it I would have your agent contact Princess to make sure you have one.
The only time I ever needed one was on an NCL cruise where the mattress was as hard as a rock. We just asked our cabin steward and he had it on the bed that night.
Cruisemates Community Leader/Moderator
Upcoming Cruise(s) Carnival Liberty: May 31, 2014. The Anniversary Getaway.
"There is a great difference between being well traveled and just having been to many places." ~Me
"Fear is the assassin of dreams." ~Me