Miss Mary Kelly was born in County Westmeath, Ireland on 19 February 1890.
She was the daughter of Lawrence Kelly (b. 1855), a farmer, and his wife Mary (b. 1862). The couple had married around 1887 and had a total of eight children. Mary's known siblings were: James (b. 1889), Kate (b. 1892), Anne (b. 1894), John (b. 1895), Edward (b. 1897) and Bridget (b. 1900) and she grew up in a Roman Catholic household.
She appears on the 1901 census with her family living at house 16, Collinstown in Westmeath. Her father apparently died not long after this and her mother never remarried. Mary would be absent from the family home by the time of the 1911 census when they were living at 18 Pakenhamhall Street, Kinturk, Castlepollard.
Mary Kelly worked as a domestic in Castepollard and hoped to find employment working for wealthy families in New York. She was also engaged to be married to a Castlepollard man by the name of John Heslin (b. 23 March 1893) who had crossed the Atlantic several months in advance of her own journey.
Mary Kelly boarded the Titanic in Queenstown, Co Cork on 11 April 1912 as a third class passenger(ticket number 14312 which cost £7, 15s). Her destination was 113 West 15th Street, Manhattan. On board Titanic she shared a cabin with two Cork girls, Annie Jermyn and Bridget Driscoll.
On the night of the disaster Mary and her cabin mates made their way to the upper decks and eventually to the forward boat deck where they were rescued in the last lifeboat successfully launched from the Titanic, collapsible D. Whilst afloat Mary helped look after the two mystery French boys, Edmond and Michel Navratil, whose father had placed them in the lifeboat before stepping back and sinking with the ship.
Mary eventually reached New York and was reunited with her fiancé. The couple were wed around 1913 and settled in Brooklyn where they had six children: Howard (1914-1993), Maureen (b. 1920), Margaret (b. 1923), Jacqueline (b. 1924), John Lawrence (1927-2004) and James (1931-1991).
Mary Kelly Heslin remained in Brooklyn for the rest of her life but did return to Ireland for a visit in later years. She died at her home in Brooklyn on 27 December 1950 and was buried in Holy Cross Cemetery.