Question: Who is Sam Marx's sibling-in-law?
Sentence (from "Minnie Marx"): Minnie Marx (born Miene Schönberg, 9 November 1864 or 1865 – 13 September 1929) was the mother and manager of the Marx Brothers, a family of vaudevillians, Broadway and film actors and was also the sister of comedian and vaudeville star Al Shean.
Relevant evidence: Yes