Dear Jen:
Carnival does have activities for older teens like your niece, however they are coordinated by the social host rather than the teen director. The line has found that teens that age don't want to do too many organized activities so instead they offer things like teen time in the disco or going to one of the shows together. While there won't be too many teens on during your late January cruise, we were on Carnival during the off season once (early Nov.) and I was amazed at how many kids and teens were aboard ship.
I hope this helps.
Smooth sailing,
Luisa Frey Gaynor
Family Cruise Editor