Elizabeth was the only daughter of Charles, 2nd Viscount Townshend and his first wife Elizabeth Pelham. On 28 November 1722 she married Charles, 5th Baron Cornwallis who in 1753 was created 1st Earl Cornwallis. His father, 4th Baron Cornwallis, was a Whig cabinet colleague of Charles Townshend. They had seven children, three girls and four boys, of whom the eldest, General Charles Cornwallis (b. 1738), was one of the leading British generals in the American War of Independence. Her younger sons were Henry (b. 1740), an army captain; James (b. 1743), Bishop of Lichfield and Coventry; and William (b. 1744), admiral and commander-in-chief of the Channel Fleet in the Napoleonic Wars. 

This painting is one of three portraits of Townshend siblings, all of which have been altered from their original 50 x 40-inch half-length size (see RN4 and RN47). The present picture has been cropped at the top and extended left and right.