With her insistence on speaking out against family violence, she has in a sense kept her murdered son alive. Luke sounds like an adorable child. He loved SpongeBob and animal onesies. He wrote love letters. His father was often homeless; on some access visits Luke would sleep in the car with him.

In one of many astonishing statements, Batty observes: 'I am the person that no one says no to. I am the bereaved mother whom everyone indulges, because there but for the grace of God go us all. I was a mum in a middle-class suburb, in a nice house, raising a nice little boy at a nice school. I was everyone and no one. And now I am Rosie Batty.' This quote sums up the content. Co-written with Bryce Corbett, the executive editor of The Australian Women's Weekly, the book explains how 'Rosie Batty', the 2015 Australian of the Year, was made.

Batty was born in in Lincolnshire, England, in 1962. Her father was a farmer, her mother a hairdresser. She has two younger brothers. When she was six, her mother, Sheila, died from a strangulated hernia. None of the children was told that Sheila had died until after the funeral. Batty identifies the trauma of this loss and the silence that surrounded it as critical formative events. She spent a few years at a Catholic boarding school, worked in a bank, then took off to Europe and worked as an au pair. She arrived in Australia on a round-the-world ticket in 1987 and never really left.

All this is covered in a few dozen pages. The story proper begins when Rosie meets Greg, the latest in a string of drop-kicks she dated when she was young. She kindly calls them underdogs. You wonder why she put up with these losers. The 'Rosie Batty' she has become never would.

'Batty is comforting and terrifying. She is protector and avenger'

As the book reveals in sometimes excruciating detail, Batty was once vulnerable and soft-hearted. When she did act to protect herself and her son from Anderson, everyone failed her: the courts; the cops; child protection. She readily admits that the system failed Anderson too.

There are many examples of chronic stuff-ups, but one will do: Batty agrees to help police arrest Anderson at Luke's footy training, but nothing happens because 'the paperwork hasn't arrived'. The undercover cops watch Anderson leave. Don't the police force use email?

We get closest to the furnace that forged 'Rosie Batty' in a devastating piece of first-person, present-tense writing called '12 February 5.45 pm'. The only witness to the murder was an eight-year-old boy. Batty's back was turned. Twenty seconds was all it took.

Rosie Batty

What really got to me was the way Batty recalls the tiny gestures of kindness at the oval and afterwards. 'Mariette hands me a cigarette and I smoke it.' A policeman called Wayne 'puts a hand on my shoulder, a gesture of tenderness I remember to this day'. On the night of Luke's funeral, a friend, Rosemary, shares her bed. 'We went to sleep holding hands. That closeness I'll never forget of being with someone rather than having to be alone.'

Batty spoke to journalists herself the day after Luke's murder, and she rightly identifies this decision as one that completely changed her life. 'This is happening to me,' she writes of that moment. 'He was my son, this is my pain. I won't have anyone speaking on my behalf.'

To answer my daughter's question, the content and the writing of A Mother's Story are compelling but, as she suggested, my own personal experience shaped my response too. Lily was born eight months before Luke Batty. There is so much joy in watching her grow up, but that only makes me feel sadder for Rosie Batty. Luke will never ask Rosie another question, but as she has powerfully demonstrated, she is still very much his mother.