She usually worked in bed by oil lamp; sometimes she painted in complete darkness. Gill consistently depicted the female form, often set against abstract, architectural lines, crosses and zigzags. The name MYRNINTEREST often appears in her pictures, which might mean ‘mine innerest self’. Her son claimed that she believed her work was guided by a spirit, although she denied this in public.
Around 1935 she began weekly séances and first showed her work at the East End Academy. By the time she died Gill had hundreds of drawings piled in her wardrobe and underneath her bed. Her work gained recognition at the Hayward Gallery’s Outsider show in 1979.