Coming from a large Irish family, Kelly took care of her brothers Donnie, Willie and Sean until a disagreement led to her leaving and becoming summarily disowned. She met Luca Brasi in New York in the early 1930s and became his girlfriend, though his ocassionally abusive behaviour led her to have a one night stand with Tom Hagen.
When Brasi discovered the affair, Kelly managed to stay alive due to revealing her pregnancy and refused to have an abortion, despite receiving a brutal beating. She later died in childbirth after the baby was delivered by Filomena. The midwife was forced by Brasi to throw the newborn into the furnace, as he did not wish for any of his race to live.