A young Sydney woman who decapitated her mother after a frenzied stabbing attack is appealing an order that would keep her behind bars until 2035.
Jessica Camilleri was found guilty of manslaughter by a jury after two forensic psychiatrists told the trial she was suffering from substantial impairment of the mind when she lost control and stabbed her mother to death.
She was jailed for at least 16 years and two months by Justice Helen Wilson in the NSW Supreme Court in March.
She has since filed a notice of intention to appeal her sentence, the court confirmed on Wednesday.
Camilleri, whose full term of 21 years and seven months ends in 2041, has until September 24 to outline what grounds her appeal will be based upon.
The horror-film fan used seven kitchen knives in the attack, four of which broke due to force, before taking her mother's head outside their St Clair home and placing it on a footpath on July 20, 2019.
Camilleri told a psychiatrist she "saw red" when her mother threatened to call emergency services to put her in a mental institution and was in a fit of rage when dragging the 57-year-old by her hair down a corridor to the kitchen.
The crime of extraordinary viciousness and brutality was made worse by the fact it was committed in Ms Camilleri's own home by her own daughter, Justice Wilson said.
"She has now lost her carer, protector, and only real friend."
Justice Wilson had described the crime as one of the most horrible manners imaginable and among the most serious cases of manslaughter.
"In light of the extreme gravity of this crime, the very great harm done, and the need to protect the community from the offender, a stern sentence is called for."