Question: Who is Mary Montagu Douglas Scott, Duchess Of Buccleuch's father-in-law?
Sentence (from "Walter Montagu Douglas Scott, 8th Duke of Buccleuch"): Walter John Montagu Douglas Scott, 8th Duke of Buccleuch and 10th Duke of Queensberry, (30 December 1894 – 4 October 1973) was a Scottish peer and Conservative politician.
Relevant evidence: No