John and Robert Brown, First Settlers of Berwick, Pennsylvania, USA

 In my blog, How Berwick, Pennsyslvania, USA, Got its Name, I asked if we can discover the first name and maiden surname of the wife, of John Brown or Robert Brown, as she was said to have come from Berwick-upon-Tweed.

Find A Grave has memorials to John, son of Robert and Mary McIntosh-Barrett;  John Brown, born 1760 died 1839, (which lists his wife as Amelia or Susan F.) and Robert Brown, died 1821, which lists his wife as Mary McIntosh-Barrett, died 1838.

On Family Search, I looked for John Brown and Robert Brown with various combinations of their birth, death, and residence but there are too many of them and I found no Mary McIntosh-Barrett, though lots of Mary McIntoshes and Mary Barretts, who died in 1838. There are no McIntosh-Barretts listed in FindMyPast.

Are this John and Robert Brown the first settlers of Berwick, Pennsylvania, USA ?

Mary McIntosh-Barrett was married to Charles Barrett who died in 1773, so her maiden name is presumably McIntosh, but I've not found a marriage to Robert Brown (except in 1873).