When Judi was 18, she fell pregnant. It was kept quiet like a dirty secret.

Writing a novel is the last thing on my mind, as I sit across the kitchen table from my Aunt Judi on a wet winter’s day in 2012. My newborn daughter is asleep in a bassinette by my side and there is a pile of washing the size of Mount Kosciuszko festering in the laundry. But then Judi tells me her story, over several cups of tea, and the terrible injustice of it itches at me long after the kettle’s cooled and Judi’s gone.

In 1970, at eighteen, the world is her oyster. The year before she’d moved to the city from the country to train as a nurse. Melbourne means freedom and Judi, like the other girls in the nurses’ quarters where she lives, makes the most of it. Only, the Catholic nuns that run the quarters enforce a strict curfew. Often it’s easier to stay out then to knock on their big double doors in the wee hours of the morning. This is where Judi’s story begins. A few months later, her father whisks her home in middle of the night, where her pregnancy is kept quiet like a dirty secret.

May Callaghan, the protagonist in my book, isn’t my aunt. Four months into her pregnancy, Judi was sent to an unwed mothers home in Sydney where she worked in a convent laundry until giving birth. After washing her sins clean with the nuns’ bed sheets, she was drugged during labour and coerced into giving her son away. May’s story is different. But the same stifling social conventions applied; conventions that robbed young mothers of their rights and subdued them with shame.

In 2013, then Prime Minister, Julia Gillard, apologised to mothers like Judi for the forced adoption policies and practises that took their children away. And, they were taken in droves. Between 1951 and 1975 an estimated 150,000 babies were put up for adoption in Australia. The majority of women who relinquished them were young and unmarried.

The senate inquiry that led to Gillard’s apology was swamped with submissions from victims whom had suffered in silence for years. Most had been secreted away to homes for the duration of their pregnancies where they were treated with disdain. The result of all this secrecy was shame.

Shame played a major role in the relinquishment of children. It silenced mothers, stripped them of their capacity to question the system, invalidated their concerns and paved the way for mistreatment and abuse. In many cases, these women carried the weight of their shame like a heavy stone for the rest of their lives.

Like Judi, they were drugged, sometimes shackled to beds, denied access to their children, deprived of basic information, lied to and separated in hospitals from ‘legitimate’ mothers. And alarmingly, many would later learn their babies were marked for adoption before consent was even given.

Judi pinned a protective medallion to her son, Andrew’s, blanket before flying home to Melbourne. She cried all the way, as she did on his birthday each year and often for no reason at all. Before she left, the nuns told her to get on with her life, to find a husband and have legitimate children. And she did, but she never forgot her son or got over the shattering grief of losing him.

As I sit across the kitchen table from Judi, my baby breathing softly nearby, I sense a connection between her story and my own and the stories of other mothers. Later, Gillard’s apology would illuminate it when she said, ‘These churches, families, medical staff and bureaucrats struck at the most primal and sacred bond there is: the bond between a mother and her baby.’

Eventually, I write a story down. It takes me three years. Not my own lucky tale or Judi’s heartbreaking one or any of the other brave women’s stories I hear during my research for my novel, Hello, Goodbye, but May’s story. It’s a story woven from the broken threads of all the others, an attempt to make something whole again.

Hello, Goodbye by Emily Brewin is published by Allen & Unwin. Out now. RRP $ 29.99