It has been a rollercoaster of a week for the 37-year-old mother-of-two, who is battling stage four cancer.

She took to social media last Wednesday night to announce her mission to sing the anthem at Origin, which at the time was to be held in Newcastle.

Less than 24 hours later - after her posts were shared hundreds of times and picked up by several local media outlets - the NRL came calling to offer her the opportunity of a lifetime.

The announcement late on Saturday night that the game would be moved to the Gold Coast resulted in a nervous wait for Amanda, but by midday on Sunday she had filled in her border declaration pass, and - along with husband Mark and sons Rhys, 13, and Evan, 12 - had arrived safely in the sunshine state by Monday afternoon.

"It would have been beautiful to do it in Newcastle, but I am thankful no matter what," she said.

Amanda was first diagnosed with breast cancer in 2016, and metastatic breast cancer of the bone two years later, having part of her spine removed after the cancer had eaten through her C7 vertebrae.

Since then, she and Mark have set to out make special memories with their boys.

Belting out Advance Australia Fair at the biggest game of the year will be the perfect chance to create such a memory.

"It's things you can't put a price on," she said.

"Because I did most of my singing before they were born, they don't have that many memories of me singing.

"So to be able to give that to them for the rest of their life would be just incredible."

Amanda is no stranger to singing the national anthem at sporting events, with six Newcastle Rugby League grand finals and a Matildas game at McDonald Jones Stadium under her belt.

But singing at State of Origin is the pinnacle for the proud Kurri Kurri girl.

"You just can't get anything better, especially coming from a rugby league-orientated town and family," she said.

"It would be the epitome of perfect."

Amanda said she has been overwhelmed by the support she has received over the past week.

"I feel so honoured and blessed," she said.

"To have everything align and my dream come true is just beyond words."

Triple M Newcastle's Tanya and Steve presented her with a $500 donation to buy the all-important outfit, and the Abermain Hawks Old Boys Club gifted her with a NSW Blues jersey to wear during the game.

The NRL has kitted out her boys with jerseys for the night, and Gold Coast stylist Amanda Barnard has donated her time to do her hair and makeup for the big performance.

The game will be broadcast on Nine. Coverage kicks off at 7pm Wednesday.