Her father John Lusby Jnr was an itinerant teacher, who found love at first sight (and "all sights after") with north coast girl Caroline Fitzhenry. His work kept the family moving from country town to country town, until they settled at Sydney in time for the Depression. Elizabeth's early memories were of the family home at Coogee, and later Roseville. She was the youngest of six siblings: Eldest Jack grew to be a cartoonist and writer for The Bulletin, Maurice a scientist, Gwen a doctor, Bob a soldier and Judith a teacher. As children, the bright young Lusbys honed their language skills on word plays.

Elizabeth spent the war years with her parents in a mostly empty nest. Jack flew with the RAAF in North Africa. Maurice went to Washington and London as Australian Scientific Research Liaison Officer (and once encountered Einstein playing hopscotch on the footpath at Princeton). Gwen commanded the Medical Division at Concord Military Hospital - one of the first women Majors in the Australian Army. Bob was captured with the 2/30th Battalion at Singapore, while Judith was recruited into naval intelligence with the WRANS, and served at the secretive Harman base in Canberra. The night the Japanese attacked Sydney, Elizabeth huddled with the other boarders in the bomb shelter at Santa Sabina College. She tried in vain to fetch the supervising nun Sr Mary Thomas, who dismissed it all as a teenage prank. The Dominican Sisters at Santa proved influential on Elizabeth - she later returned to the college as their prioress.

In 1944, Elizabeth followed her sisters into Sancta Sophia College at Sydney University, studying arts. She kept the college entertained with riotous renditions of Shakespeare ("Womeo, Womeo, wherefore art thou Womeo"), but longed for the spiritual life of the convent. On VE Day, she snuck out the window to join the Sydney street celebrations. The Lusbys already had an insight that the end of the war was coming." Mark Oliphant had once told me about this thing called an A-bomb which was about the size of a pound of butter and could knock out a city", brother Maurice recalled in 1995. "When I left London, I was given a message from Admiralty there on the date and target of the first A-bomb to land in Japan. I took it to the First Naval Member at Melbourne Headquarters. I knew what the message meant."

When liberated Australian POWs began returning through Concord Hospital, Elizabeth's sister Gwen looked in vain for her brother among the emaciated men. Through the war years, she had insisted that Japanese POWs be treated with the same care as Allied soldiers. Meanwhile, Bob had been sent to the Burma Railway, where - to "discourage sickness" - the Japanese guards bashed prisoners, withheld rations and sent men out on stretchers to sit and swing a hammer. Bob succumbed to the conditions in September 1943, dying with berri berri, dysentery and cerebral malaria at the squalid hospital camp at Tanbaya.

Elizabeth never forgot the day the telegram arrived two years later with news of his death, just as she was announcing to the family her intention to enter the convent (her mother said it was like "losing two children"). When she became a postulant on October 7, 1945, she was joining an enclosed order of teaching nuns, whose pattern of life had changed only incrementally over the centuries. They wore heavy cream and black habits and adhered to the strict disciplines of a cloistered community life. Their beautiful convent schools were self-contained antipodean echos of venerable European priories and abbeys. Outside visits even to family were forbidden.

With her final vows on May 23, 1947 Elizabeth took the religious name "Sister Mary Austin" and proved to be a great asset to the abbey. She taught mainly French, Latin and English and variously served as principal, prioress and sub-prioress at Dominican primary and secondary schools at Tamworth, Maitland, Moss Vale and Sydney.

From 1962, the Second Vatican Council crashed like a tsunami over the Dominican way of life. "We are not here to guard a museum, but to cultivate a flourishing garden of life", declared the reformist Pope John XXIII. "They opened up the windows of the church and all the nuns flew out," as Elizabeth wryly put it - though she believed that Vatican II brought about great changes, allowing the nuns to be "more individual again".

Gradually, the Dominican Sisters adopted civvies and moved back out into the community - branching away from education into other areas of ministry across eastern Australia, New Zealand and the South Pacific. "Sister Mary Austin" became "Elizabeth" again, and her cloistered existence blossomed into a globe-trotting spiritual journey, which included teaching in Noumea, and studies in New Zealand and Rome (where she met Pope John Paul II). From 1978 until her retirement in 1995, Elizabeth worked at the Signadou Dominican Teachers' College in Canberra. She loved the city and closely followed its three main sports - the Raiders, the Brumbies and the goings on at parliament. In Canberra, she also developed a passion for pottery, patchwork and crocheting, and generously farmed out her creations to friends and family.

After the separation of her early convent years, Elizabeth rarely missed a family occasion. She moved near sister Judith Follett in Fisher and proudly watched niece Rosemary Follett become chief minister of the ACT (the first woman elected to lead a government in Australia). She loved to attend playwright nephew Justin Fleming's opening nights - unfazed by eclectic subjects from Lord Alfred Douglas to Jack the Ripper - and, whether taking tea in niece Judith Fleming's Lady Mayoral Offices in Sydney, or sipping the Spritzanti Lizzie Semillon named in her honour by nephew Robert Lusby's Tintilla vineyard, Elizabeth delighted in saying "my family does interesting things!"

In 2009, Elizabeth returned to Sydney to be closer to her remaining sister Gwen, before shifting to the professional care of St Mary's Villa Concord in 2015. Elizabeth had seen off whooping cough and diphtheria as a toddler, diabetes and cancer as an adult, and taken so many operations in her stride that her family nicknamed her the "Bionic Nun". Later it was the "Electronic Nun" as she embraced the iPad and email. But the final three years were a sad purgatory of dementia, near-blindness, deafness and immobility, made worse by the isolation of the COVID-19 pandemic.

Her Dominican Sisters and close relations kept vigil through the final days, and as the chaplain performed the last rites, Elizabeth seemed to stir as if there were one last thing to say. Having been a teacher and then teacher of teachers, she might have echoed the final words of the dying schoolmaster in Goodbye Mr Chips: "I thought I heard you say 'twas a pity there were no children? But you are wrong. There were thousands."

But the final silence had come. Elizabeth died peacefully on the morning of April 30 - the old Feast of Catherine of Siena, a Dominican saint who once wrote that "nothing great is ever achieved without enduring". In the end, Elizabeth had been 75 years a Dominican. She never looked back with "rose coloured glasses" on the strictures of her early life as a nun. Indeed, many of the rules by which she lived seem impossibly harsh by modern standards. Yet, for so long in history, it was nuns who accepted living the impossible that also seemed to achieve the impossible. They carved out a space for female governance in a "man's world", and built hospital and school networks that continue to underpin the wellbeing of this and many other nations to the present day.

As Germaine Greer once wrote of the nuns who taught her: "I had a terrific education ... They brought out the best in me and it needn't have been brought out ... I could have married a stockbroker and settled into a life of three cars and a carport. They made that impossible because I was hungry for something else - spiritual values."

Indeed, The Sydney Morning Herald recently reported that of all students in the education system, it is girls from Catholic schools who are most likely to attend university, while no less than five of six of Australia's "first women" premiers and chief ministers were convent school educated - starting with Elizabeth's own niece Rosemary in the ACT in 1989. These things should not be taken as coincidence. They are the legacy of the life's work of women like Elizabeth Lusby.

As her coffin was lowered into the earth at Rookwood in Sydney, the Dominican Sisters sang the Salve Regina while prioress Mary-Clare offered a final prayer in gratitude for "our Liz". With this mixing of the venerable and the vernacular, the last of the extraordinary Lusby siblings was laid to rest.