John von Neumann married Marietta Kovesi in 1929 just before leaving for Princeton. She was a brilliant economics student at the University of Budapest and a leading figure in the social nightlife of the Hungarian capital. He had known her since his early childhood.

They had a daughter, Marina, in 1935. Von Neumann was affectionate with his new daughter, but did not contribute to the care of her or to the housework, which he considered to be the job of the wife. The gap between the lively 26-year-old Mariette and the respectable 31-year-old John von Neumann began to increase and in 1936 they broke up, Mariette returning home to Budapest.

More updated bio information.

http://www.bnl.gov/bnlweb/pubaf/bulletin/1947-1995/1975/17011975.pdf

http://books.google.com/books?id=os8wjiVhz8YC&pg=PA20&lpg=PA20&dq=Mariette+kuper&source=bl&ots=4-VcL8cnXA&sig=FdfzZ29bRzduKZU8hGaW2S0rqAU&hl=en&ei=M6WtTJcZgYLyBtKs_LgE&sa=X&oi=book_result&ct=result&resnum=7&ved=0CCsQ6AEwBg#v=onepage&q=Mariette%20kuper&f=false Page 19 on… ‪Making physics: a biography of Brookhaven National Laboratory, 1946-1972‬ By Robert P. Crease

http://www.nytimes.com/1993/06/10/obituaries/dr-j-b-kuper-83-a-nuclear-physicist-at-brookhaven-lab.html

"Mariette, Dr. Kuper's wife of 55 years and a fellow worker at Brookhaven, the former , died six months ago. ( 1993 )."