Looks like you are having a great family trip!
I always loved Williamsburg, and visited many times when I was stationed at Langley. If you have the time I would recommend visiting Fort Monroe in Hampton.
Visit | Fort Monroe Authority
Also the Mariner's Museum in Newport News.
The Mariners' Museum and Park - America's National Maritime Museum (marinersmuseum.org)
I would add that Ft Monroe has the US Coastal Artillery Museum. And the Mariners Museum has a full scale replica of the USS Monitor (the hull and turret only) that you walk about on the deck. They also have the guns, engines and many artifacts taken from the wreck.
The US Marine Corps museum in Quantico is fantastic with many full scale dioramas. Chris