Stronach was the only child of John Stronach, a marine engineer who had immigrated from Scotland, and his wife Helen née McDonald. She was born in
Balmain, a suburb of
Sydney, and attended private school until she was 12 and, after this, she was educated by a governess until the age of 15. Because of her father's heritage and the work that he did Stronach and her family spent significant periods in
Scotland during her childhood. In 1920 the family returned to Sydney where, alongside caring for her aging parents, Stronach became a partner in a tea and sandwich shop. In 1930 she joined the
Young Women's Christian Association in Sydney and she ran their cafeteria from about 1935. This was possible as both her parents died in the 1930s which freed her from her caring responsibilities. == The Australian Women's Army Service ==