She was the daughter of Richard Powys, MP, and his wife, the former Lady Mary Brudenell, daughter of George Brudenell, 3rd Earl of Cardigan. Elizabeth's sister Mary married James Stopford, 2nd Earl of Courtown. Following their father's death in 1743, their mother remarried, her second husband being Thomas Bowlby, MP.
- Hon. Georgiana Townshend (1761-1835)
- Hon. Mary Elizabeth Townshend (1762-1821), who married General John Pitt, 2nd Earl of Chatham
- John Thomas Townshend, 2nd Viscount Sydney of St. Leonards (1764-1831)
- Albinia Ann (1765-1770)
- Horatio George Townshend (1766-1773)
- Frederick Roger (1770-1782)
- Hon. Frances Townshend (1772-1854)
- Hon. Henrietta Catherine Townshend (1773-1814) who married Charles Montagu-Scott, 4th Duke of Buccleuch, and had children
- Sophia Charlotte (1777)
- William Augustus Townshend (1776-1816)
- European Royal History Journal: volume 9.6, pages 23-28.
- G.E. Cokayne; with Vicary Gibbs, H.A. Doubleday, Geoffrey H. White, Duncan Warrand and Lord Howard de Walden, editors, The Complete Peerage of England, Scotland, Ireland, Great Britain and the United Kingdom, Extant, Extinct or Dormant, new ed., 13 volumes in 14 (1910-1959; reprint in 6 volumes, Gloucester, U.K.: Alan Sutton Publishing, 2000), volume II, page 370
- Mosley, Charles, editor. Burke's Peerage and Baronetage, 106th edition, 2 volumes. Crans, Switzerland: Burke's Peerage (Genealogical Books) Ltd, 1999.
- Lewis Namier; John Brooke (1985). The House of Commons 1754-1790. Boydell & Brewer. pp. 1–. ISBN 978-0-436-30420-0.
- L. G. Pine, The New Extinct Peerage 1884-1971: Containing Extinct, Abeyant, Dormant and Suspended Peerages With Genealogies and Arms (London, U.K.: Heraldry Today, 1972), page 263.
- Joseph Edmondson (1785). The Present Peerages: With Plates of Arms, and an Introduction to Heraldry ; Together with Several Useful Lists Incident to the Work. J. Dodsley. p. 173.
- "Thomas Townshend, 1st Viscount Sydney". The Chislehurst Society. Retrieved 29 January 2018.
- "Household of Queen Charlotte 1761-1818". Institute of Historical Research. Archived from the original on 15 March 2007. Retrieved 30 January 2018.