If your niece likes things like trivia, name that tune, bingo, casinos, lounging by the pool, bocce or shuffleboard, or just reading, she shouldn't be bored (some ships also have artist lofts -- where there is painting, acrylics, or photography-- and culinary classes -- which have to be booked WELL in advance, like when they open up) she will really be fine. Some people her age actually like talking with elders and hearing their experiences (and the elders -- at least some of them and we're among them) love talking with younger generations.