Kathleen Folbigg has had her convictions for killing her four children quashed.

On her first night of freedom, Kathleen Folbigg said her "face muscles hurt from smiling so much".

Now six months later from being pardoned and freed from prison in June, Folbigg's convictions have been quashed and she is a free woman.

After spending more than two decades in jail over the deaths of her four children, Folbigg has been acquitted — the NSW Court of Criminal Appeal quashing her convictions on Thursday morning.

As the decision was announced, applause filled the court.

Watch: Kathleen Folbigg Statement. Post continues below.

It comes after an inquiry heard there was reasonable doubt about her guilt following new scientific discoveries.

In a final report released in November, inquiry commissioner Tom Bathurst KC found there was an "identifiable cause" for three of the deaths and Folbigg's relationship with her children did not support the case that she killed them.

The appeal judges agreed that the mother's diary entries — controversially used during her trial to help secure her convictions — did not contain reliable admissions of guilt. Folbigg consistently told police and a previous inquiry the entries reflected her feelings of failure as a mother after the deaths of three of her children.

Outside of court, Folbigg was supported by loved ones. Her lawyers have previously indicated the possibility of seeking compensation from the state.

Back in 2003, Folbigg was handed a 25-year minimum sentence after being found guilty of three counts of murder and one of manslaughter over the deaths of her four children. She has always maintained her innocence, claiming her babies — Caleb, Patrick, Sarah and Laura — died of natural causes between 1989 and 1999.

Folbigg and a friend outside of court on Thursday morning. Image: AAP.

Rare genetic variants later identified in Folbigg and her daughters triggered an inquiry into her conviction not long after a 2019 examination. 

The CALM2-G114R variant impacting the calcium-binding calmodulin protein was found to be a "reasonably possible cause" of Sarah and Laura's deaths, according to cardiology and genetics experts. Patrick may have died from a neurogenetic disorder, which could have hospitalised him before his death, experts told the inquiry. The inquiry was told the cause of Caleb's death at 19 days remains undetermined.

In a statement, Folbigg's lawyer said this case reminds us that "we are all human and our legal system can make mistakes".

"We have the capacity to do great things in the pursuit of truth. It is Ms Folbigg's hope that the legal system will thoroughly investigate sudden infant deaths before seeking to blame parents without good reason to do so. This case should reignite the discussion to strengthen the interactions between law and science," the lawyer said.

Folbigg herself also noted that her release is "a victory for science".

Listen to the True Crime Conversations episode about the evidence in Folbigg's case. Post continues below.

Following the pardon, Folbigg's life looks incredibly different to what it did for some decades. 

Folbigg said for the last 20 years she spent in prison, she always thought of her four children, grieving and missing them terribly. She spent the majority of her time behind bars in Sydney's Silverwater prison but was transferred to the Clarence Correctional Centre in Grafton in 2021.

She has been residing at a friend's private farm in the Northern Rivers region of New South Wales.

She has been meandering the property, playing with the dogs, petting the guinea pigs and feeding chickens. Hugging the horses also "filled her heart up", her friend noted.

For Folbigg, it's the simple things she is most looking forward to in this new chapter.

As her friend said to 9News: "She slept for the first time in a real bed, had a cup of tea in a real crockery cup, with real spoons to stir it. Decent tea, real milk. That sounds basic to you all, but she's grateful."

Technology will take some time to get used to. It's understandable, considering that when Folbigg went into prison, there were no mobiles, no Wi-Fi, no streaming platforms.

Ultimately, Folbigg is taking things "one step at a time". And considering all she has endured, it feels like the best approach.

Spending time with those she loves, Folbigg on her first night of freedom ate slices of pizza and plenty of garlic bread, sipping on a Kahlua and Coke.

It was a feeling 20 years in the making.

This article was originally published in June 2023, and has since been updated with new information.

Feature Image: Supplied.