I once read that good children's picture books weren't about plot or character or a moral or pretty pictures - they were a conduit for building the relationship between adult and child.
No other type of book becomes such a shared experience. Sitting down with your children and getting lost in a good picture book in the early evening can restore your relationship with them and reaffirm the bond of love, no matter how itchy and scratchy the day has been, or how often they've been plonked into time out.
Viewed from this perspective, Mahy's picture books can be credited with not just entertaining children (and adults) around the world for the past 40 years, but with strengthening the bonds between parents and children. I can't find a figure for the number of Margaret Mahy books that have been sold around the world - the word millions has been thrown around since news broke of her death yesterday - but by the New Zealand Book Council's count she's written more than 120, and they've been translated into 15 languages.
She received almost every accolade in children's literature, from the New Zealand Post Children's Book Award last year and its predecessor the Goodman Fielder Wattie Award, to the Esther Glen Medal, to the international Carnegie Medal and Hans Christian Anderson Award. She also held an honorary doctorate from the University of Canterbury and was a member of the Order of New Zealand.
But her real legacy is much more intimate.
If each of the picture books she sold around the world represents a moment in which a bond has been strengthened, however slightly, between a parent and a child, then Mahy's true impact on families in New Zealand and overseas has been immense.
And, although it's a great shame her wild imagination has been stilled, her legacy will keep gaining momentum. Her work will continue to facilitate those moments between adult and child, and those moments where a child, reading under the blankets by torchlight, ticks over ever so immeasurably towards the teenage years, and into adulthood.