Mulvany, Isabella Marion Jane (1854–1934), educator, was born on 4 September 1854 in 7 Clanbrassil Terrace, Dublin, the second daughter in a family of seven children of Christopher Mulvany (1818?–1895), an engineer, and his wife Isabella (née Fowler). An older sister and a younger sister died, one in infancy and one as a young woman in 1877, and there were two other sisters and two brothers. Christopher Mulvany as a young man was chief assistant to Sir John Macneill (qv), involved with surveying and proposing new railway routes in Ireland. In 1845 he became engineer to the Grand Canal Company, and remained in that post, giving distinguished service for forty-five years. Family tradition records that one evening he saw a young lady fainting on the canal bank and escorted her to her lodging; they married on 15 February 1849 in the Dublin registry office. He was catholic, though later became a protestant; Isabella Fowler was protestant and from England. Her background was somewhat mysterious; she seems to have been connected to several gentry and aristocratic families in Ireland, but was probably illegitimate and had been reduced to great poverty after her mother's death.
Young Isabella Mulvany was educated at home (the family had moved to Rehoboth Terrace, Dolphin's Barn) until she entered Alexandra College, Dublin, in 1868. She sat the first TCD examination to be organised for women (1870), and in 1872 in the junior examinations for women was awarded a first-class certificate in Latin. She was awarded a Governesses' Association scholarship, which allowed her two years of free education in Alexandra (1872–4). Mulvany stayed on from 1875 as a pupil teacher and as private secretary to Anne Jellicoe (qv), the founding lady superintendent. In 1880 Isabella Mulvany became lady principal of Alexandra School. This was a preparatory establishment, set up in 1873 to prepare girls for the college, but it was struggling financially, with around £600 in debts. Mulvany's impressive personality, and her teaching and administrative ability, set the school on a firm basis, and pupil numbers increased from 67 in 1880 to 250 in 1889. New facilities were needed, and by 1888, the school was able to pay £1,000 for a building plot. Mulvany was instrumental in raising another £3,500 and also had a major input to the planning of new buildings, which opened on Earlsfort Terrace, beside the college, in September 1889.
Mulvany was principal of Alexandra School for almost forty-seven years, not retiring until July 1926. She disapproved of much of the contemporary educational fare for young women; in her view, women should not be educated for a traditional feminine role, but should cultivate reason and intellect. As well as her influence on generations of Dublin schoolgirls, Mulvany was an important role model for women seeking higher education. She and three of her teaching staff matriculated in the Royal University as soon as it was set up in 1879, and in the autumn of 1884 were among the first nine women who graduated BA from the university. Mulvany was thus one of the first women graduates in Ireland. She probably did not much enjoy being listed in the newspapers as one of the 'nine Graces', and certainly would not have liked being identified (by the London Morning Post of 10 April 1885) as one of the 'sweet girl graduates' who attended Alexandra, princess of Wales, at the graduation ceremony in the Royal University in 1885. In 1881, along with students from Alexandra College, Mulvany registered in the Royal College of Science for a course in physics, but did not proceed to graduation.
Mulvany achieved another symbolic breakthrough for women in education in July 1904, at the first commencements ceremony held in TCD after it had opened its degrees to women. She was the first woman to sign Dublin University's register as a graduate, having been awarded the honorary degree of Doctor of Laws. A notable figure in the wider circles of educational representation, she was for many years president of the Irish Women Graduates' Association, and was elected to represent women associate members of the Irish Schoolmasters' Association on that body's standing committee. She spoke for secondary-school headmistresses on an education consultative committee, which was somewhat unusually interdenominational in composition. She was one of the founding committee of the Central Association of Irish Schoolmistresses (and subsequently its president). This body lobbied inter alia for proper training and registration of secondary-school teachers.
Mulvany's views were also influential in debates on the future development of university education for women. Some of the pioneers of women's education in Ireland, including Henrietta White (qv), who was principal of Alexandra College from 1890, were not much in favour of co-education, and in particular regarded the opening of Trinity College to women students as a threat to the existence of the separate education of girls in such de facto third-level establishments as Alexandra College and Victoria College, Belfast. Mulvany did not share this view; she saw equal education in mixed educational establishments as the way forward for female opportunities in academic life and also in wider employment. Mulvany's relationship with White was professionally polite but not warm, and colleagues would have acknowledged that Mulvany could be brusque and overbearing. Girls were generally afraid of her, according her respect rather than affection.
In retirement Mulvany lived in rooms in the Royal Hibernian Hotel on Dawson Street, Dublin. She suffered a stroke in early 1934, and died on 7 April 1934. An Isabella Mulvany scholarship was established in 1927 in her honour in TCD to mark her retirement. Isabella's sister Elizabeth Leeper (1865–1934) was one of the founders of the Irish Society for the Prevention of Cruelty to Children, and worked as honorary almoner for the society for many years. Elizabeth's husband was Richard R. Leeper (qv); they were grandparents of Richard Leeper McClelland (qv). Another descendant of Christopher Mulvany is the poet Richard Murphy (b. 1927), whose autobiography The kick (2002) apparently takes its title from an incident in his childhood when he enraged his great-aunt Bella by kicking her.