Stella Marie Mullen (13 May 1887-19 January 1978) was born to James L. Mullen (1861-1941) and Mary Hynes (1860-1933) of Covehead, and later of Charlottetown. Stella's brother, Louis W. Mullen (1896-1953), saw active duty in World War I, and her sister, Viola E. Mullen (1899-1987), was active in sports. Viola became a nun, but she left the convent to become a teacher of invalid children in Boston. Other sisters listed in the 1911 census were Ethel B.(1888-1973), who became a successful businesswoman with her fashion company, The Sportswoman, Inc., in New York and Palm Beach; Leah M. (b. 1890), who with her husband, Henry Gregory Jenkins, owned the similarly successful fashion house of Jenkins of Paris, based in Paris France; and Annie (1892-1968) who married Ray MacDonald of Charlottetown. Their youngest sister, Blanche J. (1894-1900) died of measles.

Stella Marie Mullen married Francis (Frank) P. Hennessey on 27 November 1916. Frank had courted Stella for many years until he was established in his profession, business and property holdings. As soon as their home was completed, they married, and all their children were born and grew up in it.Their eldest son's birth occurred a few days after the Halifax Explosion in 1917, and since most of Charlottetown's medical professionals were gone to Halifax, F. P. had to trudge through a snowstorm to collect a nurse to assist with the birth. Family legend says that he carried the nurse to his home on his back in the storm. F. P. and Stella had four children: Francis "Frank" Louis (1917-1987; m. Dorothy Saunders); Ambrose "Amby" Everett (1919-1946); Stella "Bonnie" Ethel Blanche (1922-2004; m. Ernest Joseph Howatt); and Louis (Lou) W. (1924-2008; m. Mary Mitchell).