Gabrielle Woutersz sentenced to more than nine years jail for killing mother

Her daughter Gabrielle had tried unsuccessfully to bury the body in a raised garden bed before leaving bloodied towels near the shower.

And when her father arrived home from work, he found his daughter cooking eggs naked except for her underwear, and the grisly scene outside.

Woutersz was arrested that day and admitted the killing in her first court appearance, saying she "100 per cent did the murder".

Prosecutors pursued the young woman for the most serious crime on the books, arguing the psychosis was caused by her abuse of drugs like ice, while her defence said it was the woman's schizophrenia behind her mental state at the time and it lowered her moral culpability.

But after a month-long trial in which the jury was unable to unanimously find her guilty of the more serious crime, Woutersz pleaded late last year to manslaughter with diminished responsibility.

Woutersz, 26, dressed in sandals and the maroon clothing of the woman's prison, flicked her long, black hair as she sat in the ACT Supreme Court on Wednesday waiting to hear her fate.

The woman was "very unwell" at the time of killing, Justice Hilary Penfold said as she delivered a sentence on Wednesday before a pack court. She accepted Crown submissions it was a violent and grotesque death.

The judge found her culpability for the crime was not increased because of her drug use, and further her culpability was lessened because her mental impairment at the time of the killing was so high, beyond what was necessary to meet the question of diminished responsibility.

She jailed Woutersz, who has been in custody either at the Alexander Maconochie Centre or the Dhulwa mental health facility since she was arrested, for nine years and nine months, setting a non-parole period of five years. Woutersz will be eligible for release in October next year.

Justice Penfold warned the woman that if she were to take drugs, or stop taking her medication, once released from prison, authorities would have not choice but to lock her up again.

That was not to frighten you, Justice Penfold told Woutersz, but to let you know how important it is for you to stay away from drugs. Not just so she did not go to prison, she said, but "so you don't do any more harm to the people ... who love you."

On October 14, 2014, Woutersz cracked her mother's skull open with multiple blows from a hammer.

She had only recently returned from Perth, where she was employed as a sex worker and was abusing ice.

She went to the Canberra Hospital the day before the killing looking for help, but staff refused to admit her.

Woutersz stayed in the waiting room for 20 hours, wrapped in a blanket and either sitting or curled up on a couch.

She went to her parents home at 9 the next morning. She seemed well. They were to help her get her life back on track, and were talking about approaching the RSPCA for a job.

On October 14, 2014, her father Keith, a public servant, left for work leaving Woutersz and her mother at home. Neighbours heard heavy metal music playing.

At one point during the day, a cousin called the house phone and Woutersz told him she had "f--ked up" with her family. At one point, Woutersz and her mother fought.

Woutersz collected a rope and a hammer and used the latter to knock her mother out. She placed her on a chair and cut the older woman's hair. She used a terracotta pot to strike the woman's head.

Woutersz then tied her mother's body to a ladder by her feet and dragged her to an elevated garden bed.

She started to empty the soil and tried to lift her mother into the raised bed before giving up.

There was an attempt to clean the house and herself, putting bloodied items in the bin, and cleaning the hammer but leaving bloodied towels near the shower.

When her father, Keith, arrived home that afternoon he found his daughter in the kitchen cooking eggs and wearing only a g-string. He found Cheryl's body in the backyard.

The court heard that Woutersz' family, who filled the ACT Supreme Court room, still supported the woman, and did not provide victim impact statements. Her father declined to speak to the media when he left the court after the sentence.