A 42-year-old mother has been charged with murder and two serious attempted-killing offences after her three children were found with stab wounds in a car at Valley Heights in the Blue Mountains, leaving her five-year-old son dead and his two younger siblings critically injured.

NSW Police charged the woman on Tuesday after she had been treated in hospital for stab wounds of her own. She faces one count of murder, recorded as a domestic violence offence, and two counts of causing grievous bodily harm with intent to murder.

The charges are allegations and have not been proven in court. The woman has been refused bail and the case is now before the courts, where prosecutors will be required to prove the offences beyond reasonable doubt.

Emergency services were called to Waratah Road at Valley Heights shortly before 1pm on Sunday after members of the public discovered a parked vehicle containing the woman and three children.

A five-year-old boy was found dead at the scene. His siblings, aged one and three, suffered serious stab wounds and were taken to the Children’s Hospital at Westmead, where they underwent surgery.

Police said the surviving children remained in a critical but stable condition following treatment. The 42-year-old woman was taken to Westmead Hospital and was later charged after investigators were able to speak with her and progress the case.

The discovery was made by members of the public, including people who stopped to provide first aid before paramedics and police arrived. Senior officers described the scene as extremely distressing for those who encountered it.

Investigators initially said it was too early to confirm the relationship between the four people or discuss a motive. By Monday, police confirmed the woman was the children’s mother and said the matter was being treated as a domestic violence incident.

The father of the children has been contacted and is receiving support. Police have said they are not looking for another person in connection with the stabbings.

Those updates show why caution is important in the first hours after a major crime. Early reports correctly said a woman and three children had been found injured or dead, but police had not yet established publicly who was suspected or how the people were related.

As the investigation developed, detectives were able to provide more information and then lay charges. The case has therefore moved from an unexplained fatal incident to a criminal prosecution.

Charging a person does not determine guilt. The police allegation must now be tested through the judicial process, and the accused retains the presumption of innocence.

The murder charge concerns the death of the five-year-old boy. The two additional counts allege that the woman caused grievous bodily harm to the younger children with an intention to murder them.

Intent is a significant element for prosecutors to prove. Serious injuries alone do not automatically establish an intention to kill, and evidence about the circumstances of the alleged acts will be central to the eventual case.

Police have not publicly established a motive. Speculation about why the incident occurred would therefore be inappropriate while the investigation continues and the accused has not entered a plea to the allegations.

The case has been classified as domestic violence related because it involves alleged violence within a family relationship. That classification is important for crime data and the way authorities assess patterns of violence, but it does not answer the unresolved question of motive.

NSW has experienced sustained concern about domestic and family violence, with governments expanding crisis support, coercive-control laws, police responses and programs intended to protect victims.

Cases involving alleged violence by a parent against children create particular difficulties because the usual public discussion about leaving an abusive partner or seeking protection may not capture the circumstances surrounding harm within a caregiving relationship.

Child protection, mental health, family support and policing can all intersect, but the existence of a tragic incident does not by itself demonstrate that a particular agency had prior knowledge or an opportunity to intervene.

Police said the woman was not previously known to them in connection with the type of incident now under investigation. There has been no public evidence that authorities had received a warning that this specific event was about to occur.

The two surviving children are now at the centre of both a medical response and a broader family tragedy. Their recovery will depend on the severity of the injuries and the outcome of treatment, while their privacy will be particularly important as the criminal case attracts public attention.

Media reporting involving child victims generally avoids unnecessary personal information, especially when surviving children may later have to live with permanent online records of the case.

The five-year-old boy who died also should not be reduced to the circumstances of his death. Police and courts may eventually release further factual information, but responsible reporting does not require publishing every detail available about a child victim.

The alleged scene inside the vehicle will be examined through forensic evidence. Investigators are likely to rely on medical findings, physical evidence, electronic records, witness accounts and any statements lawfully obtained.

Detectives have also appealed for information from anyone who was in the Valley Heights area or may have dash-cam footage. Material showing the vehicle’s movements or the timing of events could assist investigators in reconstructing what happened.

The woman appeared before the court from hospital, reflecting the injuries she also sustained. Her medical condition may affect the practical timetable of early proceedings but does not change the legal standard that applies to the charges.

Courts often adjourn serious criminal matters for weeks or months while police compile briefs of evidence and prosecutors review the case. Murder proceedings can take considerably longer before a trial or other resolution.

That means the public should expect periods with little new information. The absence of daily updates does not indicate that the investigation has stopped; much of the work in serious cases takes place outside public view.

The language used now will matter later. Descriptions such as “murdered by” or definitive statements about who carried out the stabbings should be avoided until guilt is established. The accurate formulation is that police allege the mother committed the offences and prosecutors have laid charges.

The case has shocked the Blue Mountains community, particularly because members of the public encountered the scene during an ordinary Sunday afternoon and attempted to help.

Support services will be important not only for the surviving family but also for witnesses and first responders. Exposure to severe violence involving children can have significant psychological effects on people who arrive at a scene without warning.

The immediate priorities are the treatment of the two surviving children and the progression of the criminal case. Police will continue gathering evidence while the accused remains before the courts.

The mother’s nationality or ethnic background is not relevant to the elements prosecutors must prove. The criminal case turns on the evidence about the alleged acts, the injuries and intent. Responsible reporting should therefore avoid turning ethnicity into an explanation for conduct when police have not identified it as relevant to motive.

What is established at this stage is grave enough without speculation: a five-year-old boy is dead, two younger children have suffered critical injuries, their mother has been charged with murder and two counts alleging an intention to kill, and the allegations will now be tested through the NSW justice system.