Joan Heenan was born in Fremantle in 1910 to Jessie Grace Townsend, a nurse, and Ezekial Benoni McKenna, an accountant for Western Australian Government Railways (WAGR). Joan's maternal grandfather was Mayor of Bulong and her paternal grandfather a police inspector in Kalgoorlie, so she had familial links to the goldfields. Jessie McKenna volunteered to return to nursing in Fremantle during WWI, setting up the 8th AGH, for the wounded from Gallipoli, so Joan spent time being cared for by her paternal grandparents.

She completed her schooling at Sacred Heart Convent in Highgate, where the nuns encouraged their pupil's ambitions. As Joan recalled in an interview in 1989 the idea was '...if you had ability...you should use it'.

She studied Arts at the University of Western Australia (UWA) in 1927 and after graduation in 1930 worked as a primary school teacher. After experiencing teaching and deciding it was not for her, she enrolled to study Law at UWA in 1931, completing articles with O'Dea and O'Dea, staying with the firm until December 1936. Some firms in Perth would not engage women lawyers, so it was not easy to find a firm at which was willing to allow a woman complete articles. Despite the Depression there was plenty of work at O'Dea and O'Dea, who were at that time acting for prominent goldfields identity Claude de Bernales.

Joan married Eric Heenan on 14 January 1937 and moved to Kalgoorlie. Eric had already been elected as Labor MLC for the North East province in 1936, taking in areas of what were then the Kalgoorlie and Murchison gold mining districts. Joan moved immediately into the '...midst of a very busy legal practice' at Heenan and Heenan Law firm in Kalgoorlie as well as being closely involved in his electoral campaigns. She assisted her husband in court and carried out other legal work in the office. When war was declared, many men enlisted and Joan remained the only permanent lawyer in Kalgoorlie.

Work in Kalgoorlie, which she described as a 'man's town', was a formative experience for her. Joan's clients were the workingmen and women of Kalgoorlie, and she is particularly remembered for her assistance to Italian internees during WWII. Although elections were postponed during the war she remained involved in the electorate and she encouraged her clients and local residents to enrol to vote.

A son Eric was born in 1945. After his birth, Joan worked spasmodically at the Kalgoorlie offices and in 1950 the family moved to Perth, '...Kalgoorlie was no place for a woman', and for her son's education. She purchased new practice premises in 70 St Georges Terrace and with her husband's encouragement, set up EM Heenan & Co, in Perth and also became the agent for the Kalgoorlie firm Heenan, Hartrey & Co. Eric continued to travel and work in the Parliament in Perth and in his Kalgoorlie electorate and legal practice. He left politics in 1968 but continued to practice law.

In 1983 the family practice merged with Northmore Hale Davey and Lake and Joan continued to practice law until her retirement in 1991.

She died in Perth January 2002.

Sources used to compile this entry: Criena Fitzgerald and National Foundation for Australian Women, Karlkurla Gold: A History of the Women of Kalgoorlie-Boulder, Australian Women's Archives Project, December 2012, http://www.womenaustralia.info/exhib/wikb/wikb-home.html; Interview with Joan Mary Heenan, 1989, OH2539; State Library of Western Australia; Cornish, Patrick, 'Obituary', West Australian, 2002; West Australian, 8 February 1991; West Australian, 19 March 1986.