The proposition published in the Scots Peerage comes from volume two of Alexander Nisbet's System of Heraldry: "Sir David Scott of Buccleuch, his son (son of Sir Walter Scott of Murdiston, afterwards of Branxholm), made a very great figure in the time of King James III. both in peace and war : By his lady, who was a daughter of the Somerville family (c), he had several sons; Sir Walter, the eldest, (from whom a. lineal descent in the house of Buccleugh is continued), Sir Alexander Scott, who was Rector of Wigton, and Lord Register in the reign of King James III. from the 1483 till the 1488, that he lost his life, with the king his master, at the unhappy field of Bannockburn (d)"
https://archive.org/details/systemofheraldry02nisbuoft/page/279/mod...
I do not think that this lady’s profile should be deleted, although I believe that it should be disconnected from the family tree of Thomas, Lord Somerville.
This lady appears to have been a member of the Somerville family but the name of her father is not known. The published records of Scotland may be silent about her marriage to Sir David Scott of Branxholm (formerly of Murdiston) but it does not follow that the manuscript evidence referred to by Alexander Nisbet should be dismissed out of hand.
