Kathleen was hysterical, while Susan had been stabbed more than 50 times. She was dead.
A week earlier, the sisters had come to blows over a hair straightener, with the pair inflicting bites and scratches on one another – but the seemingly normal sibling squabble could never have foreshadowed the horror to come.
It would later be revealed that Kathleen, an arts student at the Australian Catholic University, had planned the attack in advance, googling quick methods of killing, and buying three kitchen knives from Kmart in preparation.
Twice that morning, Kathleen had approached Susan, intending to stab her, and twice she lost her nerve, changing her mind. What was described in court as the "final straw" came when Kathleen attempted to use the family computer, discovering Susan had changed the password.
Mourners at Susan Worrall's funeral. Photo / Supplied
She lay in wait, and when Susan came out of the bathroom, her older sister launched at her with the knife, stabbing her repeatedly in the neck and back as she cried out "No Kathleen! I love you, I love you, please stop!"
In the immediate aftermath of Susan's death, Kathleen told a friend "I'm glad the bitch is dead". She also told forensic psychiatrist Olav Neilssen that her sister was callous, and thought she was "Little Miss Cute and Popular".
She claimed Susan had threatened her life on previous occasions, telling her "I could murder you, Mum and Dad would stick up for me".
Initially charged with murder, Kathleen pleaded guilty to the lesser charge of manslaughter on the grounds of being in the grips of "substantial impairment" due to her psychological state at the time of the offence.
Kathleen had a hormonal condition called congenital adrenal hyperplasia, affecting the production of important hormones such as cortisol and testosterone. Sufferers often experience rapid growth as children, and females often experience unwanted facial hair, 'masculine' features and fertility issues.
Kathleen had been on strong drugs to control the condition, but had stopped taking her medication in the lead up to Susan's death, hoping to lose weight. She described herself as "a 20-year-old girl who looked like a gladiator".
The cessation of medication had resulted in a surge in hormones and, by August 2008, Kathleen had the testosterone of an adult male. While much was made at the time of these testosterone levels contributing to her uncontrollable rage on October 10, the actual cause of her psychological impairment was found to be an existing mood disorder which was contributed to by her sudden cessation of hormone-controlling medication.
Justice Elizabeth Fullerton found Susan's "horrific death" would not have occurred without Kathleen's medical condition and the potential for her psychiatric state to be undermined by her failure to take her medication.
The distinction is important to advocacy group Intersex Human Rights Australia, which stated at the time it was concerned over the portrayal of individuals with congenital adrenal hyperplasia (CAH) in the context of Kathleen's case.
"CAH is not a mood-altering disorder as has been reported," the group stated. CAH individuals generally contend with salt-wasting and a lack of cortisone (the hormone that helps the body to react to physical injury). "High testosterone levels do not of themselves give rise to homicidal ideation."
Kathleen was sentenced to a maximum of six years' jail for manslaughter, and was led sobbing from the court as she mouthed "Thank you. I love you" to her parents.
It was a devastating conclusion to a horror ordeal, but for John and Maureen Worrall, the nightmare was far from over.
While testifying in her daughter's trial, Maureen broke down, saying they simply wanted Kathleen to get well and be back in her family's arms as quickly as possible. Yet less than two months into her sentence, their lives were torn apart once again.
When the couple arrived to visit Kathleen at the Dilwynia Women's Correctional Centre, in Sydney's north west, they were met at the door by staff who informed them that she had died.
Kathleen had been discovered lifeless in her cell that morning. A coronial inquest found the 22-year-old had died of thromboembolism, with obesity being an indirect cause.
It was the final tragic blow for a family that had already suffered indescribably.
Deputy State Coroner Scott Mitchell thanked the Worralls during the inquest into their daughter's death, saying they had the respect and sympathy of the entire court.
"Mr and Mrs Worrall have been through the most horrendous things," he said, "It is a tribute to their love of their daughter that they are here today, faithful to her memory."
Maureen wept as she spoke before the hearing began.
