Question: Who is Priscilla Bertie, 21St Baroness Willoughby De Eresby's maternal grandfather?
Sentence (from "Priscilla Bertie, 21st Baroness Willoughby de Eresby"): Through her grandmother Mary Wynn, Priscilla Bertie was a descendant of the Welsh princely house of Aberffraw.
Relevant evidence: No