Melbourne woman Sandra Pankhurst, the subject of the award-winning book The Trauma Cleaner by Sarah Krasnostein, has died.

Pankhurst suffered from a serious pulmonary condition and was believed to be in her late 60s but the exact cause of her death and precise age were unknown.

A lawyer acting on behalf of the family confirmed her death late on Thursday night.

“She passed away after an extraordinary life with her family around her and her dog Moet,” Matisse Mitelman said. “The relationship started as a lawyer and client but it developed into a much broader and more diffuse friendship. She’s a spectacular and incredibly empathetic person.”

Pankhurst became something of a celebrity after Krasnostein’s book on her life became a bestseller in 2018. It won multiple awards including the Victorian prize for literature and the Douglas Stewart prize in the NSW Premier’s Literary awards for non-fiction.

Pankhurst went on to become a motivational speaker while continuing to run her successful business STC Services, which specialised in cleaning premises after homicides and suicides and clearing the homes of hoarders and illegal methamphetamine manufacturers.

In media interviews, she was extraordinarily candid about her abusive childhood, her previous work as a drag queen, sex worker and funeral director, and transitioning to Sandra in the 1980s.

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Krasnostein paid tribute to Pankhurst on Thursday saying she was “utterly unique”.

“I’ll be forever grateful that she allowed me to tell the story of her incredible life and for everything she taught me along the way,” the author said.

Podcaster and founder of the women’s empowerment initiative Girls with Hammers, Kerryn Vaughan, said Pankhurst had been a guest speaker at the organisation’s annual conference only two months ago.

“Sandra was an exceptional human being,” she said. “I have no idea where so much strength and self-love came from considering the immense challenges she faced throughout her life.”

Vaughan said it was clear in early May that Pankhurst was suffering serious breathing difficulties.

“But she showed up and didn’t let anybody down. That was her thing – she never wanted to disappoint,” she said.

“We had built a wonderful friendship over the past two years and had many raw conversations. I pray her new wings will carry her safely into her next chapter and that she will finally find peace.”