Following up on that last blurb.....
Regarding sculptor Raymond Duchamp Villon
http://en.wikipedia.org/wiki/Raymond_Duchamp-Villon"Of the six Duchamp children, four would become successful artists. He was the brother of:
Jacques Villon (1875–1963), painter, printmaker
Marcel Duchamp (1887–1968), painter, sculptor and author
Suzanne Duchamp-Crotti (1889–1963), painter"
Edited to add.....Raymond being a sculptor, Jacques went by the surname of Villon and Suzanne from what I can find signed her work S. or Suzanne Duchamp.......which brings us back to Marcel (or another totally different Duchamp family)