O'Brien, Mary Lucy (1923–2006), missionary sister and doctor in Africa, was born Nora Veronica O'Brien on 17 August 1923 in Ballinderry, in the parish of Cummer, near Tuam, Co. Galway, the second eldest in a family of four girls and four boys of Michael O'Brien and his wife Nora (née Connolly). She was educated in the Mercy convent in Tuam. In February 1943 she joined the Missionary Sisters of the Holy Rosary, based in Killeshandra, Co. Cavan, as a postulant, and underwent her religious formation there, adopting the name Mary Lucy. Professed as a religious sister on 28 August 1945, she trained as a doctor and qualified MB, B.Ch. and BAO in UCD in 1952. The next year she was sent to Nigeria. She was awarded a diploma in tropical medicine and hygiene in 1959, and worked in mission hospitals in west Africa for fourteen years. In 1964 Sister Lucy (as she was most commonly known) and her colleagues opened the St Charles Borromeo hospital in Onitsha, Nigeria; she was medical superintendent. During the terrible war (1967–70) between the region of Biafra and the federal government, Onitsha was for a time the capital of the breakaway Republic of Biafra, and the hospital and many other buildings in the city were repeatedly shelled and bombed. The casualties from both sides, along with refugees, overwhelmed local medical facilities. Sister Lucy and other aid workers in Biafra worked in dreadful and dangerous conditions, and subsequently witnessed the famine that devastated the region. Along with hundreds of other expatriates, she had to leave Nigeria when conditions deteriorated further.
She was therefore able to proceed with delayed plans to travel to England for specialist training in gynaecology, and obtained the MRCOG in 1971, after which she was sent to Sierra Leone, where she spent four years. In 1976, after a year's study leave in Rome, she took up a post in Zambia as obstetrician and gynaecologist in Monze Mission Hospital, later known as Monze District Hospital. Working there until 1999, she treated and operated on thousands of women and facilitated the postgraduate training of hundreds of doctors. Thanks to Sister Lucy's expertise, Monze became Zambia's national centre for repairing fistulas; operations very substantially improved the quality of life for poor Zambian women. However, from the 1990s on, the AIDS epidemic in Africa brought ever greater challenges for health care; the incidence of fistulas and other gynaecological problems increased, as did psychological and physical suffering, and governments in the region found it almost impossible to provide even basic medical support in hospitals and clinics.
Sister Lucy was central to many efforts to cope with Zambia's health crisis; she was a member of the board of the medical council of the country and of the national AIDS advisory committee, and served on the board of University Teaching Hospital, Lusaka, and the executive of the Church Hospitals' Association of Zambia. Her friends and relatives in Ireland were pressed to assist with fundraising, both for AIDS relief and for other projects in Zambia that she initiated or assisted after her official retirement in 1999. Rotary Club members in Clonmel, and others elsewhere in the Irish midlands, collected funds for an orphanage in Lusaka, continuing support even after her death. When the Co-operative Society's shop in Newcastle, Co. Tipperary, was closed down in August 2004, the members agreed to donate funds to charities, rather than distribute the money among themselves; Sister Lucy used the €10,000 she received to establish a farm in Zambia as a development project.
Sister Lucy's work was recognised by the Royal College of Physicians of Ireland when she was made an honorary fellow in 1998. President Levy Mwanawasa awarded her the Order of Distinguished Service, First Division, in 2004, for her lifetime of service to the women of Zambia. She died on 10 April 2006 in Lusaka, and in accordance with her own wish was buried in Chikuni Mission near Monze.