Pauline Boty (March 6, 1938-July 1, 1966) was a British artist and the only female painter in the British wing of the Pop Art movement.
Biography on Wikipedia: https://en.wikipedia.org/wiki/Pauline_Boty

Celia Birtwell and Some of her Heroes by Pauline Boty
1963 / Oil on canvas / 59 4/5″x48″ / The Berardo Collection, Lisbon, Portugal

Pauline Boty on Artnet: http://www.artnet.com/artists/pauline-boty/

Further reading:
https://awarewomenartists.com/en/artiste/pauline-boty/
https://www.theguardian.com/books/2016/oct/22/ali-smith-the-prime-of-pauline-boty
https://www.nytimes.com/2019/11/20/obituaries/pauline-boty-overlooked.html