She was the second daughter of Charles Tennant (1796-1873) and Gertrude Barbara Rich Collier (1819–1918). She studied painting under Edward Poynter at the Slade School of Fine Art and with Jean-Jacques Henner in Paris.
In 1890, she married the explorer of Africa, Henry Morton Stanley, and became known as Lady Stanley. She edited her husband's autobiography, reportedly removing any references to other women in Stanley's life.
After Stanley's death, she married Henry Jones Curtis (died Feb. 19, 1944), a pathologist, surgeon and writer, in 1907.
- London Street Arabs (1890) Cassell & Co., London 
- Waller, David (2004). "Dorothy Stanley, Lady Stanley (1855–1926)". Oxford Dictionary of National Biography (online ed.). Oxford University Press. doi:10.1093/ref:odnb/41313. (Subscription or UK public library membership required.)