Kenelm Winslow's wife and ancestry has been a matter of speculation for many years. William Cutter's 1915 New England Families gave his father as William and his wife as Catherine. In a series of articles in the 1960s, John G. Hunt examined the clues in the relations of Edward Winslow (son of Kenelm b. 1599). Edward was a gentleman, and his father was not, suggesting that his mother was a gentlewoman. In addition, in letters from the 1600s, Herbert Pelham and Sir Arthur Hesilrige (and his wife Dorothy Grevill) refer to Edward as "cousin." The Winslows also had close connections to the issue of Kenelm Burke. In a series of articles in the 1960s, John G. Hunt suggested the following male line:
Galfrid1 Winslow of Earls Crome, co. Worcester, 1425; Richard2 of the same 1430; William3 of the same 1471; Richard4 of the same, will dated 1546; Thomas5 of Kempsey; Kenelm6 of Kempsey and Worcester.
Hunt also examined the various connections of the Pelhams and the Hesilriges to find a connection that would lead those men to call Edward Winslow "cousin." He ultimately considered, and rejected, the theories that:
In 2000, Kenneth Kirkpatrick (NEHGR Vol:154 pp.78-108) examined Hunt's work as well as additional information on the families of Pelham and Hesilrige and came up with a theory that Edward Winslow's mother (Kenelm's wife) was a Greville, daughter of Sir Fulke Greville, buried 11 Dec 1559 at Alcester Church, Warwickshire, England. Fulke's memorial indicates that he had three older daughters not named in his will. The timing fits with the wife of Kenelm, and it would make Edward second cousin to Pelham and Hesilrige, as well as giving him other relatively powerful connections among the heads of the Massachusetts Bay Colony (but not close enough to raise the question as why his status was clearly not as high as theirs). Because Elizabeth Morgan's mother was a Greville, this explanation also explains the connections to her family that Hunt relied upon in posing that theory. The parish registers of the relevant areas are not extent, and further records do not appear to have been examined as of yet, and thus this too remains just a theory.