Second child dies after Blue Mountains stabbing, third child still critical - ABC News & Headlines – Australian Broadcasting Corporation

A second child has died after a stabbing in the NSW Blue Mountains on the weekend. (ABC News: Patrick Thomas)

A second child has died after a mother allegedly stabbed her three children in the Blue Mountains on the weekend.

NSW Police said the child, aged one, died on Thursday in hospital after the children were attacked at Valley Heights near Springwood on Sunday.

It comes after one of the child's siblings, a five-year-old boy, was found dead inside the vehicle police responded to on Waratah Road.

The mother was also found at the scene with self-inflicted stab wounds, police have previously said.

Police were told members of the public performed first aid on the children before emergency services arrived.

A third sibling, a three-year-old who also sustained stab wounds, remains in a critical condition in hospital.

The woman has been charged with a second count of murder and is due in court in November. (ABC News)

The woman was charged with murder and police said the mother has now been charged with an additional count of murder.

She is due to face Penrith Local Court in November.