I am also a descendant of Wm McComb and Rebecca Kearsley.I looked in my files and found the following:
(Judge) John Kearsley (1745-1819), the 2ndchild of Jonathan Kearsley (1718-1782) and Jane (1720-1801), m. Nancy Morrow (- 1801).Nancy was John’s first wife.John and Nancy had seven children.
My source is the book “The Descendants of Jonathan Kearsley, 1718-1782, and his wife Jane Kearsley, 1720-1801, (from Scotland,) who settled at Carlisle, Penn’a […]” by Elmer L. White, 1900.
Also according to a footnote in the book:“The Record of Deed Transfers […] gives name of wife as Agnes Morrow.Inquiry among the old Scotch-Irish residents of Cumberland County elicits the information that Nancy is a nickname for Agnes; therefore the name is correct in both places.”
The only other Morrow I show is the same as one mentioned by Craig Laird.