A solo mother of two daughters, Mahy didn't feel financially secure enough to start writing fulltime until 1980. Up to then, she worked by day as a librarian and, after her children were asleep, wrote stories.
Friend and biographer Tess Duder said she doubted Mahy got more than four hours' sleep a night; yet she produced hundreds of children's stories, novels for young adults and poems many of which were published around the world and translated into German, French, Spanish, Dutch, Norwegian, Danish, Swedish, Finnish, Italian, Japanese, Catalan, Afrikaans, Russian, Chinese and Icelandic.
Mahy was recognised with numerous awards including the Hans Christian Andersen and Carnegie Medals as well as being appointed to the New Zealand Order of Merit, open to only 20 living people at one time. Mahy died in 2012, shortly after being diagnosed with cancer.