Paul Frecker has this sketch, "Miss Ethelreda Spencer-Churchill was born on 15 June 1829. Her father was Lord Charles Spencer-Churchill (1794-1840), second son of the 5th Duke of Marlborough. She died on 24 October 1881." This does not accord with thepeerage's articles about Spencer-Churchills.
From Paul Frecker; sepia tone removed (and replaced in the border) and image size increased by half by gogm.