In 1981, she received a Bachelor of Arts degree in English literature and political science from Victoria University of Wellington (including studying under Bill Manhire).

In 2005 she received a Master of Arts degree in creative writing from the International Institute in Modern Letters, Victoria University of Wellington.

[1][2] In 2013 McCallum co-founded Mākaro Press with her son Paul Stewart in Wellington, New Zealand.

[3] Their first book was Eastbourne: An Anthology, which McCallum also co-edited with Maggie Rainey-Smith and Anne Manchester.

[6] McCallum has published in a number of literary journals including short stories in Turbine (2008)[7] and poetry in Landfall (#133, 1980).

[1] McCallum has been a feature writer for New Zealand Listener, Dominion Post, The Press, New Novel Review.