The granddaughter of the British naturalist Charles Darwin, Barlow began her academic career studying botany at Cambridge under Frederick Blackman, and continued her studies in the new field of genetics under William Bateson from 1904–1906.
Her primary research focus when working with Bateson was the phenomenon of herostylism within the primrose family.
In later life she was one of the first Darwinian scholars, and founder of the Darwin Industry of scholarly research into her grandfather's life and discoveries.