Her family moved to New Zealand in 1948, where she grew up on a farm in the Wairarapa region and went to a Catholic boarding school in Wellington.
[2] Her first book, Women in the House, was published in 1993, and provides biographical information about the 36 female members of Parliament in New Zealand who were elected from 1893 to 1993.
[2] In 1992 she was awarded the National Library Fellowship to research early women journalists in New Zealand.
[3][4] This research work led to her second book, Women and their Words: Notable Pioneers in New Zealand Journalism, which was published in 2009.
[6] A review in Northern Advocate concluded "McCallum did exhaustive research for this book, and the reader is rewarded for it".