Mrs Weston manages the Winnunga Nimmityjah needle exchange program, and exudes a kind of elegant equilibrium behind her reception window in Narrabundah where she hands out about 400 needle packs a month.

It's not that she's immune to the tragedies in the indigenous community, having had more than her own share, but she has come to the view the best anyone can do is "just get on with it".

Mrs Weston says that in fact, many of the people who come for clean needles are not indigenous. She suspects some in the indigenous community go elsewhere to avoid being identified, which might also explain why non-indigenous people come to Winnunga for needles. She doesn't ask what drugs they're taking, since her job is to keep people safe, not scare them off with questions but, surprisingly, she suspects that for at least some of the men body-building is the driver.

Mrs Weston's road to Canberra was circuitous.

She was born on the very remote Murray Island in the Torres Strait, where her father was a pearl diver until his boat was confiscated by defence for use during the second world war. The family was given the option to evacuate in the face of a feared Japanese arrival.

They moved to Brisbane, where a young Thelma arrived in a white school speaking no English. Mrs Weston says she met no other indigenous people in those early years, with neighbours and school friends all white, an accident of upbringing she credits with a healthy sense that she was just part of the community like everyone else. Her life had no sense of "them and us".

She nevertheless left school in year 7 because the family could not afford to keep sending her, and worked in a laundry before entering nursing in an army hospital. There, she met her Scots-heritage husband, a patient.

She has only been back to Murray Island twice since she was child – the airfares and distance are prohibitive – but still treasures a journal in which her mother translated 131 Christian hymns into the Murray Island language, in meticulous longhand, for the family to sing.

One of the ironies in Mrs Weston's family story is the fate of her Welsh grandfather, who owned a beche-de-mer boat in the Torres Strait area. He came to an unhappy end when he was killed by two disgruntled workers, his body lost at sea. The workers were young Aboriginal men, found in possession of one of the lugger's dinghies. Both were hung for their crime.

Mrs Weston has beaten the odds on indigenous life expectancy by many years herself, but a long life comes at a cost. Three daughters have died, the most recent of breast cancer in her early 40s in 2011. She farewelled her only brother in February.

She brought up her family in Perth, where her husband's family lived, and returned to Perth in 2014 on the Indian Pacific to scatter the ashes of her husband and two of her daughters, one of whom died of asthma in 1980, aged 19.

Despite the sadness of these losses, Mrs Weston faces her own circumstances and the wider tragedy of indigenous health and disadvantage with a kind of stoicism. As a young and newly trained nurse, she thought to cure her people of every ill. Now she sees a job so vast and intractable there is no easy answer.

She might have moved to Canberra in 2004 as a retiree, but with a 9 till 5 job at the Winnunga needle exchange, and a son, daughter and grandchildren in Canberra, her days are busy and her focus is simple: just get on with life, do some good at work, and and keep her family safe.