 Lady Arabella Denny was a supporter of the Dublin Foundling Hospital, which had been established to care for children abandoned due to poverty and/or illegitimacy.In 1760 she presented a clock to the Dublin Workhouse; it was put up in the nursery for foundling children and used to regulate the feeding of infants.She was instrumental in the reforming of the Foundling Hospital and in 1764 was thanked by the Irish House of Commons for her "extraordinary bounty and charity".