Ethel Lilian Voynich, née Boole (May 11, 1864–July 27, 1960) was an Irish novelist and musician, and a supporter of several revolutionary causes. She is best known for the novel 'The Gadfly' (Wikipedia page ) refers: the book can be found on the Project Gutenberg website as ).
She was born in Cork. Her father was George Boole , the mathematician, her mother, born Mary Everest  - niece of George Everest  after whom the mountain is named - and she was married to Wilfrid Voynich in 1902, having lived with him for a number of years and changed her surname to Voynich (through an announcement in The Times adverts).
Her sisters were:
- Mary Ellen (1856–1908) - married Charles Howard Hinton (Wikipedia page ).Their children were George (1882–1943), Eric (*1884), William (1886–1909) and Sebastian (1887–1923) inventor of the Jungle gym . Sebastian had three children: Jean Hinton (married name Rosner) (1917–2002) peace activist. William H. Hinton (1919–2004) visited China in the 1930s and 40s and wrote an influential account of the Communist land reform and Joan Hinton (1921–2010) worked for the Manhattan Project and lived in China from 1948 until her death on 8 June 2010; she was married to Sid Engst.
- Margaret (1858 – 1935) married Edward Ingram Taylor, an artist. Their elder son Geoffrey Ingram Taylor became a mathematician and a Fellow of the Royal Society.
Their younger son Julian was a professor of surgery.
- Alicia (1860–1940) - Married name Alice Boole Stott, who made important contributions to four-dimensional geometry, Wikipedia page .
- Lucy Everest (1862–1904) who was the first female professor of chemistry in England, Wikipedia page .
Her biography on Wikipedia is at .