Mary Vera Marshall Armstrong (1904-1992) was a British children's author and active proponent of the Girl Guides movement. She was born in Huddersfield, West Yorkshire, in 1904, and was published under both her maiden name, as Vera Marshall, and under her second married name, as M. Vera Armstrong. Her books often involved Girl Guides, and she herself served the movement in various capacities, including as editor of the Girl Guides magazine, The Trefoil, from 1954-66. She was awarded an MBE in 1974 for her work with the Guides. Armstrong died in 1992, in Stroud, Gloucestershire.