MacCallum was born in the small village of in Lower Saxony 1863, where she married in 1882. She had met her Scottish-born husband,
Mungo William MacCallum, in
Aberystwyth in west Wales, where he was a professor, and she was teaching French and German. She emigrated in 1886 to Australia, where her husband had become a professor at the
University of Sydney. She had her interests but became a hostess, which assisted her and her husband's career. She was a supporter of women's suffrage and she became the President of the Sydney University Women's Sports Association (SUWSA) in 1910. She had been a leading figure of the University Tennis Club and this was one of the three clubs that merged to create the SUWSA. 24 women students were present, this was a lower percentage representation than for male students. Each of the women present were asked to sign their commitment to support the SUWSA as the new body intended to challenge the monopoly of the Sydney University Sports Union (of men) over the university's playing fields. One of the two dozen women was
Jessie Lillingston who would go on to lead similar challenges to the patriarchy. In 1914, the
Sydney University Women's Union was formed. In time, she would be the Union's patron. MacCallum was a founder of the
National Council of Women of New South Wales and president in 1919–28. In 1926 her husband became a Knight Commander of the Order of St Michael and St George and she became Lady Dorette MacCallum. MacCallum worked for
The Infants' Home Child and Family Services the
Sydney Day Nursery and Nursery Schools' Association, the
Australian Board of Missions, the Royal Society for the Welfare of Mothers and Babies and the New Settlers' League of Australia. == Private life ==