John's mother was Sarah Salmon Ketchum.
Henry married secondly, after 8 Jun 1655, Sarah (Salmon) Ketcham, daughter of Christopher and Anne (Taylor) Salmon and widow of Edward Ketcham of Stratford, CT. That she was the widow of Edward Ketcham is proved by a suit brought on 11 Jun 1660 by Henry1Whitney against Joseph Whitmore for stealing the affections of his wife's daughter, Sarah Ketcham. Her birth date and place, presumably England, and death date and place, probably Norwalk, CT, are unknown. Several unreliable sources place her baptism as 9 Jul 1608, Laxton, Nottinghamshire, but that child died in 1612. Presumably she was a second daughter of the same name, and born after 1612, but her baptism has not been found.
History and Genealogy of the Families of Old Fairfield, Volume 1
edited by Donald Lines Jacobus