The heartbroken founder of one of Australia’s rising activewear brands has shared the devastating news of her younger sister’s death, paying tribute to the 17-year-old she calls her “soulmate” and “warrior”.

Justine Ramsay, a professional athlete and co-founder of Gia Active, revealed her sister, Giaan Ramsay, has passed away, describing her as “too kind and too sensitive for this world”.

In an emotional post on Instagram, the 27-year-old entrepreneur and runner from the Gold Coast, Queensland, described the pain of losing Giaan, who inspired the brand’s name and its mission to champion mental health.

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“My beautiful angel sister, I can’t even believe I’m sitting here writing this, it still doesn’t feel real that you are gone,” Justine wrote.

“Anyone who knows me knows my sister Giaan was my whole entire world.

“She was my light and my soul ... we understood each other on a level no one else will understand.”

Let down by health system

While the exact circumstances surrounding Giaan’s death have not been made public, Justine shared her belief her sister had been let down by the health system.

“She was failed by the medical system, and I will never stop fighting for her,” she wrote.

“They never allowed her to have a voice, so I will be her voice.

“I owe it to her to make sure no one else feels the same, because they failed my girl, and now I have to try to live without her.”

Describing Giaan as “loving, thoughtful and the funniest person I’ve ever met, selfless even in her darkest hours”, Justine’s tribute paints the picture of a young woman full of heart, humour, and creativity.

“She would make my belly laugh every day.

“She was so beautiful, we used to say she looked like a doll, because she was just perfect. In every way.”

Giaan passed away at just 17 years old.

The family is now raising funds through a GoFundMe campaign to reunite relatives from South Africa and cover funeral costs.

The campaign, launched on July 30, has raised nearly $35,000 in a matter of days, with support pouring in from across the country.

“We love you, our beautiful Giaan,” Justine wrote on the page.

“You were an angel too kind for this world.”

Born from heartbreak, driven by purpose

In a recent behind-the-scenes video posted by Gia Active, Justine shared the deeply personal story behind the brand.

She revealed she had been a runner since the age of six, living in activewear and dreaming of creating her own pieces, but a severe injury two years ago forced her out of sport for over a year and a half, leaving her feeling isolated.

“I just like lost who I was because all I’ve ever known is running,” she wrote.

Gia Active became her way of turning pain into purpose.

“Gia is actually named after one of my beautiful sisters — Giaan,” she shared.

“She’s a true warrior and someone who embodies perseverance and resilience like I’ve never witnessed before.”

“I want Gia Active to not only reflect my passion for sport and activewear, but to honour my sister and anyone else who has faced mental health battles.”

The brand recently announced 5 per cent of proceeds from its latest restock will be donated to the Black Dog Institute, a leading organisation supporting mental health research and education.

‘Forever 17’

Justine ended her tribute with a heart-shattering farewell reflecting both her unimaginable grief and her fierce determination to keep Giaan’s memory alive.

“Everything I do and everything I am is because of her.

‘She taught me strength, resilience, courage — and what’s truly important in life.

“Forever 17. Rest in peace, my sweet girl.”

If you need help in a crisis, call Lifeline on 13 11 14. For further information about depression contact beyondblue on 1300224636 or talk to your GP, local health professional or someone you trust.