21+ days on Crown Princess with 2 kids unde 10?

I'm thinking about taking my kids on a long cruise on Crown Princess, and I'm on the fence.

This would be our first long cruise (we usually do 7 nighs, never Princess before), and I'm not quite sure if it would be the best experience for them.

They do love cruises. However, to my understanding, Princess is in general for an older crowd, and I'm wondering if they will get bored or not if there are not enough children in the kids club to keep busy and if there are not enough activities on the ship that would work for their age.

Also, I'm a bit concerned about getting sick and being stuck on a ship.

I would love to hear your experiences with kids on long cruises fellow cruise fans!