We will be on this cruise. We have cruised with NCL several times but this is our first time on the Jewel and the first time sailing from New York. I am sure that you will find a lot of people onboard in your age range. The penthouse suite sounds nice. We will be in a balcony room. You should check out Cruisecritic where there are a lot of people posting about this cruise.
I have been on this ship. It has a large range of ages. There are many different shows that appeal to different audiances. The entertainment is wonderful. The decor is more kid friendly, as it is a more family style cruise.