Elizabeth FitzGerald (before 1597–1611) was the first wife of Lucas Plunket, who succeeded as Baron Killeen in 1613, and who in due course became the 1st Earl of Fingall in 1628.
She was believed to be the daughter[1] of Rory O'Donnell, 1st Earl of Tyrconnell, and Lady Bridget FitzGerald.
Understood in the same way to have been Elizabeth O'Donnell, she was reported to have married Luke Plunket, 1st Earl of Fingall.
[2] Her lineage as a daughter (possibly pre-marital) of Rory O'Donnell, 1st Earl of Tyrconnell, and his wife Lady Bridget FitzGerald, was repeatedly cited in various peerage directories, such as Lodge's (1827, and re-issued in 1907),[3] Foster's (1881),[4] Cokayne's (1926),[5] and Burke's (1980).
[7] Later sources confirmed this, i.e. that this Elizabeth was a FitzGerald, the Countess Lady Bridget's sister, and not her daughter.