Elouise and Danny Massa apologised to two of their children for leaving early again as they headed out to ensure their youngest son's legacy.
Their successful advocacy after the death of their two-year-old will help prevent a repeat of the tragedy, by keeping the most important hospitals under public control.
Joe Massa died after he and his parents waited three hours in the emergency department of Sydney's Northern Beaches Hospital in September.
But proposed laws introduced on Thursday will prevent a repeat of the controversial public-private partnership at the hospital elsewhere.
Holding a pair of her son's "quite worn and weathered" shoes, Mrs Massa said every person in the state deserved better than the care her son received.
"This is one step in the right direction to ensuring that," she told reporters.
Mr Massa said the law would bring huge change out of a tragic event.
"With Joe's Law, his legacy can live on, so it's huge for us as a family and as the parents," he said.
A review into Joe's death found an IT system not used in government-operated public hospitals had failed to alert nurses and doctors to the boy's concerning heart rate.
Hospital officials have also blamed anchor bias towards an initial diagnosis of gastro, rather than giving him IV fluids to treat the fluid loss affecting him.
Healthscope, which operates 38 hospitals across the country, is contracted to operate Northern Beaches Hospital until 2038.
But financial turmoil at the Canadian-controlled firm has placed its future in doubt.
Premier Chris Minns on Thursday guaranteed the Sydney hospital's emergency department would not close.
But he resisted speculating on the future of the contract, pending an audit of hospital management.
"Healthcare should not primarily be about making a profit," Mr Minns told reporters.
"It should be about saving lives and ensuring people get healthy.
"Clearly, that didn't happen for baby Joe. The Massas have shown that we need to do everything possible to ensure that another family doesn't go through the same tragedy."
While noting difficulties in doing so, he did not dismiss buying out the contract to resume total public control.
The partnership at the hospital, which replaced two smaller public facilities in 2018, was set up under the former coalition government.
Health Minister Ryan Park said no more public hospitals would be privatised.
Doctors welcomed the decision after raising the alarm about the hospital for years.
"The PPP (public-private partnership) model put profits before patients, stripped away public oversight and left frontline staff dangerously unsupported," their union's executive director Andrew Holland said.
Private partnerships will still be used for elective surgeries amid a backlog of about 100,000 procedures.
Opposition Leader Mark Speakman said the coalition respected the family's brave advocacy amid unimaginable grief, but is yet to see the bill or discuss whether to support it.
Joe collapsed after significant fluid loss, followed repeated failures by hospital staff to do basic observations or respond to his mother's concerns.
The Massa family had earlier called for public hospital care to be protected in law to prevent further privatisation.
The spotlight is expected to remain on operations at Northern Beaches Hospital.
A parliamentary inquiry will investigate serious incidents at the facility and how management responded, while an inquest is expected into Joe's death.
The company's chief executive previously vowed hospital management would ensure they learned from Joe's tragic death to ensure such incidents never happen again.
