	Turnbull was born in Mosgiel, Otago, on 2 May 1885 to Catherine Armstrong, a milliner, and Sydney Turnbull, a baker. Her parents emigrated from Scotland in 1864. Turnbull was the youngest of eleven children. She attended East Taieri School from the age of 6 to 14. Turnbull had aspirations to become a teacher but her family could not afford to keep her in school. Her family attended the East Taieri Presbyterian Church.