At the age of 17, Hill moved to Chicago, allegedly to work as a prostitute at the 1933 World's Fair and later became a waitress. During this time, she met a mobster named Joseph Epstein, a ranking associate of Chicago Outfit political corruptor Jake Guzik. Hill allegedly became Epstein's mistress, party hostess, and a co-conspirator in his bookmaking ring. In the process she became a close associate of several high-ranking Outfit mobsters. She was eventually the mistress of Frank Costello, Frank Nitti, Charles Fishetti and Joe Adonis.
She also became a "bag woman", and funnelled Outfit funds into Swiss bank accounts. She later denied it, but it is known that she bought a new home for her family in Marietta for $10,000 - in cash.