The daughter of James St John Jeffreyes of Blarney Castle; in 1793 she married Richard Butler (1775-1819) eleventh baron Caher and first earl of Glengall. She was the original of Lady Singleton in Lady Morgan's novel O'Donnel.

CORRESPONDENCE OF Emily Butler, countess of Glengall [née Jeffreyes]:

Emily Butler, Lady Caher, to Lady Morgan, 6 November 1813 in Lady Morgan’s Memoirs: Autobiography, Diaries and Correspondence. Second Edition, Revised 2 vols (London: Wm. H. Allen & Co., 1863)

Countess of Glengall to Frances Ann Taylor, 27 August 1821 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)

Countess of Glengall to Frances Ann Taylor, 10 September 1821 in The Creevey Papers: A Selection from the Correspondence & Diaries of the late Thomas Creevey, M.P. (London: John Murray, 1903)