On Friday, Justices Kristina Stern, David Davies, and Stephen Campbell, said Gaye Grant was released on bail as her appeal against her conviction is "likely to succeed".

If successful, she will be the second teacher to have her conviction on historical child sex abuse charges quashed because she is a woman.

Grant, now 77, was arrested in mid-2021 after her victim, now a husband and father, summoned the strength to report the abuse to police.

He endured decades of pain at the hands of Grant, he told the court, as Judge Andrew Haesler sentenced the teacher in 2022 to six years and nine months' jail.

Grant pleaded guilty to maintaining an unlawful relationship with a child from when she taught at Albion Park's St Paul's Catholic Parish Primary School in the 1970s.

In an extraordinary move, Grant was successful in her bail bid before the NSW Court of Criminal Appeal on March 1.

The Helga Lam decision

Grant has launched an appeal, arguing it was a miscarriage of justice that she was convicted for a charge under which she could "never lawfully be convicted".

This late-stage challenge was filed after another teacher, Helga Lam, successfully had her historical sex abuse charges quashed in February.

Lam had been charged with 15 counts of indecent assault on four school boys for offences dating back to 1978. She denied the allegations.

The court found Lam had been charged under the now-repealed Section 81 of the Crimes Act.

This law concerned only "homosexual crimes" during a period when homosexuality was still criminalised in NSW, and did not apply to "conduct committed by a female".

It was repealed and replaced in 1984.

Despite Grant pleading guilty to her charge, she will still likely have her conviction overturned, the court said on Friday.

She offended against the boy when he was aged about 10 to 13, and she was 20 years his senior.

The sexual contact began in Grant's home when she would ask the boy to sit on her lap and fondle her breasts.

This progressed to rape on multiple occasions when the boy would stay over, with Grant telling him she loved him.

As the victim entered high school, he realised what was happening was not right, and he began to distance himself.

He ended their encounters, which prompted Grant to write a note to him in which she said words close to: "[Victim], I apologise for upsetting you. Can we still be together? I still love you and miss you. Love, Gaye OOOXXX".

"I still to this day have nightmares about this period in my life," he said during Grant's sentencing in 2022.

Law cannot be applied retrospectively

Dr. Victoria Colvin, Senior Lecturer in Law at the University of Wollongong, explained that courts are bound to apply legislation in place at the time a person is alleged to have offended.

"The court's don't have a choice in what they apply in criminal matters. In these cases, they are stuck with the statute in 1973," Dr Colvin said.

"What we can do as a society is acknowledge the trauma that these victims have suffered not just as a result of these acts, but also this process."