Painter and printmaker, born in Bristol. She was also known as Katherine Hartnell, and was the sister of the artist Hilda E Jefferies, also known as Hilda E Bonsey. Paintings were signed in her married name, Kathleen Hartnell, etchings with her maiden name, Kathleen G(rant) Jefferies. She studied at Slade School of Fine Art under Henry Tonks, Philip Wilson Steer and Walter Westley Russell, 1922–8 and 1929–30, winning several prizes. Exhibited extensively at Beaux Arts Gallery, RA, NEAC, LG, Leicester Galleries and RSA. Aberdeen and Bristol public galleries hold her work. She was also a musician, trained at the Royal Academy of Music. Lived in London.