The usually energetic and sporty 11-year-old was losing weight, always fatigued and complaining of a constant stitch.
But it was only when he threw up in his doctor's office that alarm bells really started ringing for the much-loved kid from Sydney's northern beaches.
He was taken straight to hospital for scans. Then came the news no parent ever wants to hear.
"The doctor then called me aside and said: 'Can I see you a minute in my office?'" dad Scott Hewitt told AAP.
"I went in and he said: 'Sorry to tell you, but your son's got cancer.'"
For nearly a year, Beau and his family went through cycles of treatment and rode the highs and lows of living with cancer before a devastating blow right before Christmas in 2024.
After initially being told his treatment was finished, a final scan showed the rare cancer - known as myoepithelial carcinoma - had spread.
Beau and his parents decided not to pursue further chemotherapy and focused on filling his life with the footy and fishing he loved so much.
He died on March 18, just shy of his 13th birthday, leaving his $3000 life savings to older brother Tye and thinking of other kids facing their own cancer struggles.
"He made us promise we would keep going and keep fighting for the other kids and help as much as we could," Beau's mum, Belinda Hall, said.
One potentially life-saving tool the family is banking on helping more kids like Beau is liquid biopsy.
The non-invasive ultrasensitive screening searches for cancer DNA in blood or other fluids, allowing tumours to be diagnosed and monitored.
The test is currently very rarely available for kids like Beau but the head of the liquid biopsy program at the Children's Cancer Institute says he hopes getting the test will one day be a new normal of cancer care.
"We would love it to be you just present (at the doctor) and your GP can order the test," Rob Salomon said.
"There's a fair amount of work to get to that point - to prove that it works and make it so stable that anybody can do it anywhere."
To keep that work going, Beau's family are sharing their story in the hope people will donate to the institute's Christmas appeal, raising money to bring liquid biopsy to all kids with cancer.
"You need those funds to be able to produce the outcomes all kids need," Ms Hall said.
"It was Beau's dream to help and that's what we are doing now."
Lifeline 13 11 14
Kids Helpline 1800 55 1800 (for people aged 5 to 25)
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