Just saw your post on my first visit to the KEES forum.Your locations rang bells -- and I'd love to know anything more you have on John and Sarah's kids -- especially daughter Ann.
My cousins and I have been searching for an Anna J. Keer or Kees, wife of William Conover or Covenhoven. William was born in Washington Co PA in the late 1700s, and we know almost nothing about him. He is believed to have married Anna -- we don't know anything at all about her -- then was in the Cranbury NJ area when at least some of his children were born.William's family was part of the big NJ Dutch community and may have been among those who tried settling PA but gave up during the Indian encounters and returned to NJ for good.
We don't know where he met his wife Anna, but possibly in PA.The two sons we know of were born in 1811 and 1816, suggesting William and Anna married around 1800?
Any info you'd care to pass on will be most welcome