In the month called February, 1669-70, Robert Barclay married Christian Mollison, daughter of Gilbert Mollison, a merchant in Aberdeen; and on his marriage settled at Ury, with his father.
The issue of this marriage was three sons and four daughters; viz. Robert, David, John, Patience, Katharine, Christian, and Jane; all of whom survived him, and were living fifty years after his death.
https://www.loc.gov/resource/gdcmassbookdig.shortaccountofli00beva/... (p. 20)
A long line of duplicates through this profile and ultimately connecting with George Barclay, Laird of Mathers includes one or more unproven ancestors, namely Henry Thomas Barkley
https://www.geni.com/search/matches?id=6000000202164827836&src=...
https://www.geni.com/merge/compare/6000000008630921700?to=600000020...
I found the discrepancy when comparing the descendants of both the MPs and duplicates.