Amy Staunton's mother Jennifer shares her unbearable heartbreak after a freak accident took her daughter's life

An Australian mother has spoken of the heartbreak at losing her 'vivacious' teenage daughter after a freak accident while celebrating New Year's Eve on a barge. 

Adelaide resident Jennifer Staunton said she can 'no longer do Christmas' because she feels her family is incomplete after 17-year-old Amy, the youngest of her three children and passionate equestrian, died two years ago. 

The family had been on a private boat on the Murray River near Swan Reach when Amy, who had been swimming, sat down a metre from her mother at a gap made by an open gate in the fence surrounding the barge's deck. 

'Mark, my partner, and I were there and Amy came and sat down near us, she was talking and just so happy … she was just sitting there and then she was gone,' Ms Staunton told The Adelaide Advertiser this week.

Ms Staunton and her family feel they will never have proper closure because the reason Amy fell into the water is still unexplained.

'We were stunned and in disbelief. Everyone was in shock … Amy was so strong and athletic and fit, it made no sense,' she said.

Two other passengers on the boat, an adult friend and his teenage son, dived into the water in an instant and desperately tried to find Amy who had failed to resurface.

Despite it still being daylight, the pair could find no trace of her and a frantic Ms Staunton had to be sedated and transported to hospital.

Police divers later found Amy's body after a 16-hour search. 

A coronial inquest later ruled it an accidental drowning with the coroner unable to find any trace of anything that had happened to the teenager.

There were no visible injuries, no symptoms of a medical episode such as a seizure, and the toxicology report had returned clean, refuting some reports Amy had been partying. 

Ms Staunton said despite police saying to her during the search they remained hopeful Amy had managed to swim to the riverbank somewhere, she said she knew - because of some intangible connection - that her daughter was gone before the search had completed.

The shattered mother said she still struggles daily to comprehend how her daughter, who she said was so incredibly full of life, could not be here.

'The hardest thing I do every day is to get up, to get dressed … I call it putting on my 'game face' so I can go out there in the world, to smile and do the little pleasantries. But it is absolutely exhausting.'

Amy was remembered by those closest to her as a 'gorgeous young lady' who always wore a bright smile on her face, especially around her beloved horses.

At the time of her death, her mentor and work manager Heather Currie expressed her shock at the teenager's death and sent her 'deepest condolences' to her family.  

'Amy's daily smiling face, her energy and enthusiasm, her potential, her love and care for the horses will be deeply missed at Danson Dressage,' she wrote. 

'Today we lost an angel.'

Amy's heartbroken sister Emily said her 'beautiful little sister left this world and became an angel'.

'Our world has been turned upside down and I refuse to believe this is real,' she wrote.

'We will never stop loving you Amy. ️Forever young baby girl.' 

Local boater William Hoddle warned the river contained debris and that the area in which the teenage girl fell was 'quite a dangerous spot'.

'That's why you've always got to wear your life jacket,' he told the ABC. 

Ms Currie said an esteemed Istan filly was named in Amy's honour to pay tribute to her dream of owning her own.

'She would often talk to me, telling me her plans to breed or own an Istan foal and all of the possibilities ahead,' she wrote alongside a photo of the tiny foal. 

'Danson Amy just happens to be an Istan daughter and her character, friendliness, braveness and potential will always remind us just how special Amy was.'