Well Jersey was fab. And the weather was better than mainland uk throughout. We stayed in the NE corner at Rozel camping, a really good site with pool, good park for the kids, well spaced pitches, immaculate facilities and not too big. Highly recommended -we would definitely stay there again. I didn't realise until we booked that wild camping is verboten and you have to obtain a permit to take the van over. I guess its a good way of controlling congestion.
The Durrell wildlife conserve is fab, the castle at Gorey (mont orguiel) very interactive, the cream teas and crab sarnies superb. We kayaked off Rozel beach (though pay attention to tides ad strong currents). We also liked the fact the minor roads were classed as green lanes with a blanket 15 mph limit and priority to cycles and walkers. Great beaches with clear water. The War tunnels gave good insight into the German occupation but wasn't really for the kids. The only thing that disappointed was the total disdain with which much of the population treated tourists - apologies if you hail from there, but that's how we were mostly treated.