Never stayed there but we had friend that did and they liked the place. It’s in Maryland so closer to you. https://www.cherryhillpark.com/
Other parks on the south side of town that I know about:
Prince William National Forest: https://www.nps.gov/prwi/plany…..ations.htm
Pohick Bay: https://www.novaparks.com/park…..ional-park
Of course, the kids could tent camp in our backyard and you could have the guest bedroom….(we are really close to Prince William National Forest)
My goal in life is to be the person my dog thinks I am.