McConchie was born in Auckland, New Zealand, and attended Freyberg High School in Roslyn.
McConchie has worked in the Justice Department and the Office of Agriculture and Fisheries in Wellington before she began writing professionally in 1990.
[5] McConchie has won the Best Novel category in the Sir Julius Vogel Awards for New Zealand science fiction and fantasy six times, including three for novels set in Andre Norton's worlds (by Norton and McConchie):[2] in 2003, 2005, and 2006 for Beastmaster's Ark, Beastmaster's Circus, and The Duke's Ballad.
Most recently her Ancient Egypt alternate history fantasy, Bastet's Daughters, received the International Cat Writers Assn.
In October 2012 her short story, The Domen, (Penumbra eZine May issue) won the international Cat Writers' Association (CWA) Certificate of Excellence, and continued on to win their 2012 Muse Medallion for this work.