Helen Schaw, lady of Dirleton - A daughter Alison Home m her cousin James Sauchie?

Should Helen Schaw, lady of Dirleton have a daughter Alison Home who marries her cousin James Sauchie?

"Archibald, master of Halyburton, eldest son and heir of George, 4th Lord Halyburton, married Helen [Elene] Schaw, daughter of Schaw of Sauchie. He died before his father, leaving a son, James, who succeeded his grandfather as 5th Lord Halyburton. (Douglas's Peerage of Scotland, page 322.) His relict married Sir Patrick Home of Pol wart before 28 April, 1490, and a daughter of theirs, Alison Home, married her cousin, Sir James Shaw of Sauchie. (Douglas's Peerage of Scotland, Vol. II., pp. 176, 177.) [Home was a big man in his day : w T ent on a pilgrimage to Canterbury, 1493, just 100 years after Chaucer. Sir Patrick was Comptroller of Scotland, 1499- 1502. Allison Home's sister was Abbess of North Berwick. At this period the family of Shaw must have been of great importance by reason of their position and alliances, and the offices held. (Lord Cathcart.)" https://archive.org/details/anent1884/page/103/mode/1up