Aishwarya Aswath's parents have questioned why a Perth hospital is yet to implement key staffing changes as the family examines possible compensation over the seven-year-old's death.
Aishwarya died of sepsis on Easter Saturday 2021, hours after presenting to the Perth Children's Hospital emergency department with a fever and unusually cold hands.
She had been left in a waiting room for more than 90 minutes, despite her mother Prasitha Sasidharan and father Aswath Chavittupara pleading with staff - who they described as rude and dismissive - to escalate care.
An inquest into her death was told there was intense demand on staff who missed repeated opportunities to identify the seriousness of her condition.
In her long-awaited written findings, Deputy State Coroner Sarah Linton found there was a chance Aishwarya's life might have been saved with proper treatment.
She recommended the priority implementation of nurse-to-patient ratios and a standalone resuscitation team at Perth Children's Hospital.
An emotional Mr Chavittupara said the findings vindicated the couple's long-held belief that the health system had failed their daughter.
He said the government should have acted sooner on implementing the ratios.
"The issue with staffing is not new," he told reporters on Monday.
"How are we going to shape our health system for the future (when) we're still struggling to overcome challenges which were there five years ago?"
The McGowan government has promised nurse-to-patient ratios - a key demand of the nurses union in a prolonged industrial battle - will be implemented at Perth Children's Hospital as a priority.
But in an ABC radio interview on Monday, Child and Adolescent Health Services chair Rosanna Capolingua was unable to say how many nurses would be needed to fulfil that promise.
A further 48 full-time equivalent nurses have been added to the emergency department roster since Aishwarya's death.
Premier Mark McGowan has insisted the hospital was not understaffed that night because it had its full rostered complement.
Ms Linton said while that was "technically" correct, it was clear the roster had been inadequate to deal with demand.
"Aishwarya's parents brought their daughter in to hospital because they knew she needed help," the coroner said.
"But due to the pressures on them, the medical and nursing staff missed the signs that she was critically ill from sepsis and failed to rescue her.
"It really is as simple, and as tragic, as that."
The coroner did not make any individual adverse comment against the staff members involved in Aishwarya's treatment.
But she noted there were multiple opportunities where clinicians could have escalated her care, including when a junior nurse observed Aishwarya to be grunting in pain with an elevated heart rate, respiratory rate and temperature.
The nurse was unable to monitor her because she was repeatedly called away on other duties, including assisting a patient resuscitation.
The family declined to comment on Monday about possible compensation but is understood to be pursuing an multi-million dollar ex-gratia payment from the state government.
Ms Sasidharan urged the government to act on the coroner's recommendations immediately.
"Every mother should be cherishing their children's achievements and sharing their children's happiness but I am holding my daughter's death certificate and inquest report," she said.
"I'm just asking the authorities please implement those recommendations if they think that will help and please make sure another mother (does not) have to go through the same thing."
