Fitzgerald, Elizabeth (d. 1645), countess of Kildare and patroness of the Jesuits in Ireland, was born (date and place unknown) second eldest among six daughters and six sons of Christopher Nugent (qv), 14th Baron Delvin, and his wife Mary, daughter of Gerald Fitzgerald (qv), 11th earl of Kildare. Elizabeth was probably brought up at the main seat of the Nugents at Cloneen, Co. Westmeath. Sometime after 1600 she married her cousin Gerald Fitzgerald, 14th earl of Kildare, whose estate was heavily encumbered with jointures and debts, and who was struggling to preserve his estates from the claims of a powerful English settler family, the Digbys. Out of favour with the government, deeply in debt, and facing mounting legal fees, the protestant earl was forced to cultivate the support of the catholic noblemen of the Pale. Hence his marriage to Elizabeth Nugent, which did not even include a dower, although a papal dispensation was required as they were second cousins. Indeed, the Nugents were one of the staunchest catholic families in the Pale and were frequently at loggerheads with the government. Her husband died early in 1612, leaving her with an infant son, Gerald. Initially, the government was not prepared to allow the 15th earl's upbringing to be left in the hands of his catholic mother, and Gerald was declared a ward of the crown. However, Elizabeth had a valuable ally in the person of the lawyer Richard Hadsor (qv), who used his influence at London to have Gerald placed in his mother's custody on 15 July 1612. She was also assigned two-thirds of the unencumbered remainder of the Kildare estate to maintain herself and her son. However, the Digbys continued to press their claim and the Kildare estate remained mired in litigation, preventing her from enjoying a guaranteed source of income. In July 1616, a royal warrant, authorising the securing of Elizabeth's jointure, was countermanded through the influence of the powerful courtier George Villiers (later duke of Buckingham). Alarmed by Villiers's intervention and by his links with the Digbys, Hadsor decided that the young earl needed more powerful patrons at court and that his catholic mother was a liability. To Elizabeth's dismay, in summer 1618 Hadsor arranged for Gerald's wardship to be transferred to Esme, Lord Aubigny, and for the earl to be brought to England for his education and instruction in the protestant faith. The countess wanted to raise her son as a catholic, while Hadsor, an Old English protestant, was determined to preserve an ancient noble line regardless of its religious stripe. Pleading her son's ill health, she was able to secure a delay until he died in November 1620. Legal proceedings regarding her widow's rights to the Kildare estate dragged on, but were eventually arbitrated by King James I in 1621, which led to the assignment of one-third of the newly delimited Kildare estate (including the manors of Kilkea and Graney; lands in Westmeath and Down; and customs revenues from two ports in Down) as a jointure for the dowager countess during the minority of her nephew, the 16th earl.
As part of this arrangement, she was obliged to vacate her residence at Maynooth castle and establish herself in Kilkea castle, Co. Kildare. Now financially secure, she was able to continue as a generous patron of the Jesuits having allowed Maynooth to serve as a base for their missionary work during the 1610s. Due to her wealth, social status and seigniorial powers, she proved a formidable champion of the catholic faith. When in 1623, the local sheriff began fining her catholic tenants for recusancy she complained to the lord deputy Henry Cary (qv), Viscount Falkland, who in turn ordered his subordinate to desist. She built for the Jesuits in Back Lane, Dublin, a college, a noviciate, and a sumptuous public chapel in the renaissance style, which opened in 1628. This property, known as Kildare Hall, included private quarters for the countess, where she probably lived until 1630. In 1629, she attempted to broker a marriage between her protestant nephew George Fitzgerald (qv), 16th earl of Kildare, and a daughter of the powerful catholic noble Randall MacDonnell (qv), 1st earl of Antrim. However, the government intervened to frustrate this bid to re-catholicise the earldom of Kildare, and in the end the 16th earl was wedded to the daughter of the militantly protestant landowner Richard Boyle (qv), 1st earl of Cork. Cork in his capacity as Kildare's legal guardian immediately began legal proceedings designed to overturn Elizabeth's existing jointure. In his capacity as lord justice of Ireland, he oversaw the seizure of Kildare Hall on 7 January 1630, handing it over to Trinity College Dublin for the accommodation of fifty students. His private differences with Elizabeth aside, both Cork and his colleagues were determined to terminate the missionary activities of the catholic religious orders, and perhaps saw Kildare Hall as a catholic rival to Trinity.
In 1633, her nephew the 16th earl having attained his majority, it was agreed that she would surrender her existing jointure in return for an annuity of £500 and the town and demesne of Kilkea (where she had lived) for her life. The next year she donated Kilkea Castle to the Jesuits. She also set about regaining Kildare Hall, meeting (c.August 1633) with the lord deputy, Thomas Wentworth (qv) who was thought to be tolerant towards catholicism and an enemy of Cork's. Her case came before the Irish council in spring 1634. She argued that she had leased the property for rent, and that as she had been unaware as to how her property was being used she could not justly be deprived of it. During 1634–5, Kildare Hall was restored to the countess and was used once again as a Jesuit house and as a public chapel.
Following the 1641 rebellion, she was outlawed in the next year, but probably remained resident at Kilkea Castle. After an eight-month illness she died 26 October 1645, leaving her estate to the Jesuits; the head of the mission in Ireland mourned her as ‘the mother of our society in this realm’. The countess's letters to the 14th and 16th earls of Kildare are in the PRONI. Her other private papers are not known to have survived.