SYDNEY (AP) — An Australian appeals court on Thursday overturned all convictions against a woman 20 years after a jury found her guilty of her killing her four children.

Kathleen Folbigg already was pardoned by the New South Wales state government and released from prison in June based on new scientific evidence that her four children died from natural causes as she had insisted.

The pardon was seen as the quickest way of getting the 56-year-old woman out of prison before an inquiry into the new evidence recommended the New South Wales Court of Appeals consider quashing her convictions.

Applause filled the courtroom and Folbigg wept as Chief Justice Andrew Bell quashed three convictions of murder and one of manslaughter.

Her children died over a decade ending 1999 aged between 19 days and 19 months.

Prosecutors argued she smothered them, and she was convicted in 2003 and sentenced to 30 years in prison.