Question: What American Socialite married the elder son of Edward Cavendish?
Sentence (from "Kathleen Cavendish, Marchioness of Hartington"): Kathleen Agnes Cavendish, Marchioness of Hartington ("née" Kennedy; February 20, 1920 – May 13, 1948), also known as "Kick" Kennedy, was an American socialite.
Relevant evidence: Yes