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Rita Camilleri, 57, was allegedly killed by her daughter (Supplied)

A Sydney woman accused of murdering her mother in their Western Sydney home has had her case mentioned briefly in court this morning.

Jessica Camilleri, 25, is being moved from Nepean Hospital to Amber Laurel correctional centre.

Her 57-year-old mother Rita was found decapitated late on Saturday in St Clair.

Police arrived at the St Clair home about 11.40pm on Saturday after reports of an argument between two women.

The body of the 57-year-old was found in her kitchen. Her head had been dumped down the street in a neighbour's front yard.

Several knives were allegedly found at the scene.

A four-year-old boy was inside the home at the time and is believed to have witnessed the incident.

Jessica Camilleri, 25, is being moved from Nepean Hospital to Amber Laurel correctional centre. (Supplied)

Last night, neighbour Ali Bostani told 9News he heard somebody call; “Help, help help,” before there was a knock at his door.

Jessica Camilleri asked him to call the police or ambulance saying she’d had a fight with her mum.

“She was a lovely person, she was a lovely lady,” he said today.

“I feel sorry for her because she was so nice.”

Neighbour Ali Bostani told 9News he heard somebody call; “Help, help help,” before there was a knock at his door. (Nine)

Facebook messages have emerged showing the mother had had concerns about her daughter’s mental wellbeing.

Another neighbour told 9News the pair “had a good relationship”.

Ms Camilleri did not apply for bail today, with her lawyer telling the court she had significant health issues including autism, anxiety and intellectual disabilities.

“I really need medical attention,” she told the court.

(Nine)

“I can’t move my fingers because of the incident that happened. My whole body is in agony.”

An order was made for her to be assessed in hospital before her next court appearance.

"This is up there with one of the most significant, most horrific scenes police have had to face," Detective Inspector Brett McFadden said.

"There is no stepping away from the fact that this was horrific and a significant attack, and the injuries that the victim suffered were extensive.

"It is a very difficult, challenging, confronting investigation.

"A lot of considerations need to be made, such as the background about what has happened at the address."

The family was known to police but what unfolded on Saturday night was "not foreseeable", Det McFadden said.

Forensic investigators at the scene. (Nine)

Strike Force Comeroy has been set up to investigate the incident.

A number of knifes have been seized for forensic examination and several crime scenes have been established inside the home.

Support is being provided to first responders who attended the scene, police said.