Heartbreaking update on Scarlett Oliver from Perth who made famous during Taylor Swift's Australian Eras tour

The father of a young Swiftie who got her dying wish to meet the pop superstar during her Australian tour has issued a heartbreaking update on her condition.

Perth girl Scarlett Oliver captivated the country at Taylor Swift's superstar Eras tour, seeing her idol perform after securing tickets to the Sydney show at Accor Stadium earlier this year.

She had only been given 12-18 months to live after being diagnosed with an aggressive form of brain cancer known as high-grade glioma.

In a life-changing moment, the nine-year-old was also given one of Swift's trademark black fedora hats during the performance of her song, 22, and given a hug.

The encounter was shared across the world by fans on social media.

But in a heartbreaking twist after Scarlett's brush with fame, her parents have revealed she may only have 'weeks rather than months' left.

In a statement on Instagram, her father Paul said his 'beautiful' child had not been doing well recently.

He said much of the school holidays had been spent in hospital due to complications with a feeding tube, vomiting and 'extreme tiredness'.

'Last night after discharge from hospital she suffered a significant seizure and was rushed to hospital via ambulance,' Paul told his Instagram followers on Friday.

'She has now stabilised but remains in hospital very unwell.'

He explained oncology doctors had delivered the grim news about Scarlett's dire prognosis.

'Her birthday is on May 7th and they have concerns that she will not get to enjoy that,' Paul said.

'I just want to see my baby smile and laugh if only for a little while. We are all struggling to comprehend how we are where we are.'

Scarlett's family have revealed they have been overwhelmed with birthday cards for their little girl - which she would begin reading on Sunday.

'Thanks to each and every person that took the time to do this for her,' Paul said.