NYC family Considering a purchase in one of the Litchfield towns, Brookfield, Roxbury, Woodbury, Kent et al. Have a 7 year old, 3 and 1 year old. Would have a pool . What activities / camps are best for the 7 year old DD ? Hope to find a nice option for Camp for her summers from say 8 year old ( next summer) to aged 13 . also is it like the Hamptons, where we will find many NYC families at the camps ?

Lots of stuff to do in Litchfield County. There is a good day camp at Rumsey School and also The Washington Club is open to non members for golf and tennis camps. You will find countless day camps as well like Eagle Rock, etc. There are more and more NY families in Litchfield County over the years. Some have more NYC people than others. Kent, Washington and Litchfield have a lot of NY'ers. It is very low key and not at all like the Hamptons. You can also join a country club and they usually have summer programs and you can meet a lot of new people.
My kids have done the Audubon camp in Sharon. It was 50/50 city/country. Some towns have town camps at the local park/lake and there is a tennis camp in Sharon. There's an art camp just across the border in Wassaic, NY. Plenty of horse camps too.
You can spend your entire summer hanging out with New Yorkers or you can never see another city dweller for 3 months. Your choice.