Zimmy,
Jamestown is beautiful and quiet. There is also a ferry service to Newport so you don't have the hassle of driving/parking there.
2013 Jamestown Newport Ferry Operating Schedule
South County beaches are a crapshoot right now but I expect authorities to do everything in their power to make sure those beaches are open - too important to their economy. Mackeral Cove in Jamestown is a good kids beach. Fairly shallow and not to rough. Some good restaurants in Jamestown.
DZ