In a statement released on Tuesday night, her family said the 28-year-old was running to help victims of the stabbing and van attack when she was fatally injured.

Releasing a photo of their smiling daughter holding sunflowers, Kirsty's family said she was "loved and adored by her family, friends and boyfriend".

"She was the most outgoing, kind and generous person who loved to help people," they said.

"Helping people was what she loved to do in her job as a nurse and in her daily life.

"As she ran towards danger, in an effort to help people on the bridge, Kirsty sadly lost her life.

"We are so proud of Kirsty's brave actions which demonstrate how selfless, caring and heroic she was, not only on that night, but throughout all of her life. Kirsty - we love you and we will miss you dearly."

The family asked for privacy to grieve Kirsty away from the public eye and said they will not be making any further comment on the "tragedy".

Ms Boden worked for Guy's Hospital in central London, about 300 metres away from London Bridge, as a staff nurse in theatre recovery.

The hospital said her colleagues have been informed of her death and were being supported during this "extremely difficult and distressing time".

Dame Eileen Sills, chief nurse at Guy's and St Thomas' NHS Foundation Trust, said Kirsty was "an outstanding and hugely valued" person to work with.

"Kirsty was ... described by her colleagues as 'one in a million' who always went the extra mile for the patients in her care," Dame Eileen said.

"Our thoughts at this time are with her family, her loved ones and our staff who have lost a dear friend and colleague."

Seven people were killed and dozens injured, some seriously, in the attack which targeted London Bridge and the Borough Market.

Another Australian - 21-year-old Sara Zelenak from Brisbane - remains missing in London after she was last seen running from the three attackers while wearing high heels.

Ms Boden and her family are understood to be from the South Australian town of Loxton, on the Murray River north-east of Adelaide.

A keen traveller, she ran a blog in which she identified herself as an Australian living in London and working full-time in the healthcare sector.

She described herself as "just your average dreamer, with a full-time job and a constant longing to go where I haven't been".

Recent posts detailed her travels in Milan, Sofia and Lisbon, and a trip to Kiev, Ukraine for the 2017 Eurovision song contest.

"I recognise that I might not go everywhere but I should definitely go everywhere I can, and so should you!" Ms Boden wrote.

"At risk of sounding cliche, life is short and we should all use the time we have wisely."

Before moving to London in 2013, it is understood she spent some time in Sydney where she worked as a registered nurse and a volunteer lifesaver at Tamarama Beach.

South Australian premier Jay Weatherill said his government would provide support to the families of South Australian victims of the London attack.