We're on Silhouette to Iceland and Ireland mid July, travelling with two kids. Know from our roll call that there will be a few others too, but I don't expect there to be loads.
We did the same itinerary last year on RCL Jewel of the Seas (older ship without much entertainment for kids) and had about 200 kids onboard. The kids were never an issue, but the ship being fully booked and nowhere quiet to relax because of crowds was. Silhouette has more public areas that are quiet, so I'm hoping that will be less of an issue there.
Our kids are easy going and polite. They will probably spend their time in the kids club and occasionally in the pool if the weather allows.