Chauncy was born Nancen Beryl Masterman in Northwood, Middlesex (now in London), and emigrated to Tasmania, Australia, with her family in 1912, when her engineer father was offered a job with the Hobart City Council. She attended St Michael's Collegiate School in Hobart. In 1914, the family moved to the rural community of Bagdad, where they grew apple trees. The bush setting of Bagdad, including a bushranger's cave, would inspire some of her future writing, and also a lifelong involvement with the Australian Girl Guides movement. Initially organising Guide meetings and camps at her brother's Bagdad property, Chauncy started her own Guide troop in Claremont where she worked as a women's welfare officer at the Cadbury's Chocolate Factory from 1925.Berenice Eastman, 'Chauncy, Nancen Beryl (Nan) (1900–1970)', Australian Dictionary of Biography, Volume 13, Melbourne University Press, 1993, pp 408–409.
