Siti Kamal exploited Jay Windross' social media plea for the return of his wife Dee's stolen phone, filled with pictures of their terminally ill 11-month-old Amiyah.

Kamal pretended she had the phone, taken from a bathroom at Chadstone Shopping Centre days before the baby died in April 2019, and demanded $1000 for its return.

She sought leave to appeal her maximum three-year jail sentence for blackmail labelled "so reprehensible as to be amoral".

Legal Aid barrister Tim Marsh argued the punishment was too harsh. He also said the sentencing judge had been overly pre-occupied with the morally charged nature of the crime to the detriment of other relevant factors.

Victoria's Court of Appeal on Thursday disagreed.

It found the appeal didn't have enough chance of success to warrant granting the application made outside of the usual time frame under which such bids were allowed.

"(Kamal) responded to a public plea for help from two especially vulnerable people in a terrible situation by preying upon them for financial gain," the appeal judges said.

"She persisted in her demands even after becoming aware that their plight was at its most grave.

"It was, as the (sentencing) judge said, cruel and repellent. It demanded denunciation."

Kamal exchanged nearly 160 messages with Mr Windross in the 24 hours before Amiyah's death.

Amiyah was born with an undiagnosed neurological condition. She spent 200 of her 338 days alive in hospital.

Her parents documented their daughter's short life on the Samsung S8, which wasn't backed up.

"You may help me today, god may help you," Kamal wrote, despite never having the phone.

It was still missing at the time of her sentence in March 2020.

She pleaded guilty to blackmail and was ordered to serve two years before becoming eligible for parole.

At the time, County Court Judge Liz Gaynor found little evidence to back up Kamal's claim of being driven by financial distress.

"That you should be inspired in the first place by such suffering to offend in this way, much less continue it as intensely as you did even after being told Amiyah was dying and then of her death, I find to be so reprehensible as to be amoral," the judge said in sentencing.

Kamal's visa has been cancelled and the mother of two is likely to be deported to Malaysia when she is released from prison.

Australian Associated Press