Denny (Fitzmaurice), Lady Arabella (1707–92), philanthropist, was the second daughter of Thomas Fitzmaurice (d. 1741) of Lixnaw castle, Tralee, Co. Kerry, 21st lord of Kerry, created 1st earl of Kerry in 1722, and Anne Fitzmaurice (née Petty; d. 1737), only daughter of the surveyor Sir William Petty (qv). Her mother was a friend of Jonathan Swift (qv), who wrote fondly of her good sense and intelligence. Denny's career in charity began in her native Kerry with the establishment of a dispensary for the poor in Tralee, where she is also thought to have founded an almshouse. In August 1727 she married her neighbour Colonel Arthur Denny, MP for Kerry (1727–42). Accounts passed down by her nephew William Petty (qv), 1st marquess of Lansdowne, indicate that she managed to overcome the bullying of her brother-in-law Thomas, which dogged her early married life, by taking shooting lessons; displays of her skills and her determination to use them convinced him to give up his campaign of harassment. Left a widow, and childless, in August 1742, Lady Arabella turned down several offers of marriage; her annuity of £1,000, increased to £1,500 in 1751 by an inheritance from her uncle Lord Shelburne, left her comfortably off. She moved to Dublin, purchasing a house on St Stephen's Green (1745), and enjoyed the company of her wide social circle, which included Swift and Mary Delany (qv). After making a continental tour in the early 1750s, she bought a second home, Peafield Cliff, in Blackrock, Co. Dublin. Here she set about landscaping the gardens according to the latest fashion, and caring for her niece Anne Fitzmaurice and cousin Katherine Fitzmaurice. She came to regard Anne as an adopted daughter, and left her the bulk of her estate.
Best remembered as a philanthropist, Lady Arabella's association with Dublin's Foundling Hospital began in 1758, when she responded to the house of commons findings on the condition of workhouses by suggesting that the hospital, noted for its extraordinarily high infant mortality rate, should be regularly inspected by some charitably minded Dublin ladies. She alone persisted with the inspections, and in time took over the running of the hospital. She reorganised the nursery and infirmary, where standards were appallingly low, offered premiums to nurses for their care of delicate infants, and spent more than £4,000 in enlarging and improving the buildings. In recognition of this work she received votes of thanks from Dublin corporation and the Irish house of commons, which found in 1763 that ‘the children were in general healthy, well fed and properly clothed, employed and instructed’ (Robbins, 25). Her work for Dublin's foundlings in turn brought to her attention the position of their mothers, many of whom had been abandoned by their families. This led her to establish the Magdalen asylum on Leeson Street in 1766, which she managed for many years with the assistance of her deputy, a Mrs Usher. The first such institution to be opened in Ireland, it received its first inmate in August 1767; through her influence it became one of Dublin's most fashionable charities, enjoying the patronage of Queen Charlotte. The attached chapel (opened January 1768 as a means of raising funds for the asylum) became a popular place of worship with the city's ruling class, notably the lord lieutenant and lord chancellor.
Always pragmatic, throughout her years of work with both institutions Lady Arabella advocated providing their inmates with practical skills that would serve them in later life. In overseeing instruction in weaving and lace-making in the hospital she worked closely with the Dublin Society (later RDS). Her name appears regularly in the society's minutes: in 1767 they record her giving premiums to ‘deserving children’ in the Foundling Hospital who had excelled in lace-making, and later as advising the society on woollen and worsted manufacture. A keen promoter of Irish industry, she introduced carpet weaving to Ireland (1761), and bred silkworms at her Blackrock home. For these efforts she was made patron of the Irish Silk Warehouse in Parliament Street, Dublin, and granted the freedom of the Guild of Merchants (1765) and honorary membership of the Dublin Society (1766).
Although the Magdalen asylum always remained her primary concern, she also supported the Rotunda Hospital (being appointed to its ladies’ committee in 1760), the welfare of the blind, and the Fishing Fund, the aim of which was to prevent Dutch and French boats fishing off the Irish coast. In all her work she ‘brooked no delays, shortcomings or interference’. After her retirement as manager of the Foundling Hospital in 1778 standards rapidly deteriorated. Despite declining health she continued her involvement with the Leeson Street asylum until about 1790. Her portrait was painted c.1762 by Hugh Douglas Hamilton (qv). She died 18 March 1792 at Peafield Cliff, and was buried in the family vault beneath the chancel of Tralee church. A monody on the death of . . . Lady A. Denny, written by John Macaulay, was published in Dublin later that year.