A former schoolmate of Adelaide woman Ann Marie Smith, who died in horrific circumstances while under disability care, has relayed a moving account of their long-time friendship.

In a statement read to the Disability Royal Commission on Wednesday, the woman said Ms Smith enjoyed singing along to ABBA songs, loved her dogs and had an unforgettable laugh.

The pair had gone to primary school together in Adelaide and had kept in touch during high school and as adults.

“We watched each other grow from little girls to adult women and I will always cherish our friendship through many good years,” the woman said.

But she said Ms Smith could also be headstrong and stubborn, and told the commission they did not speak with each other in the year before her death because of a falling out.

“This is something I really struggle with. I shouldn’t have made excuses,” the woman said.

“I carry a lot of guilt about that and I know that things would have been different if I had gone around to see her.

“For me, it is still incomprehensible what has happened to her.”

Ms Smith, who had cerebral palsy, died in hospital in April 2020 from septic shock, multiple organ failure, severe pressure sores and malnourishment.

She had been found to be living in squalid conditions in her own home, largely confined to a cane chair, while under the care of the National Disability Insurance Scheme.

Her death has been subject to a police investigation, with her former carer Rosa Maria Maione charged with manslaughter.

NDIS Quality and Safeguards Commissioner Graeme Head also launched an independent investigation by former Federal Court judge Alan Robertson, with his report in 2020 essentially clearing the commission in how it exercised its regulatory functions.

Mr Robertson said on the question of whether it should have acted earlier to ban Ms Maione, the commission had no information to take such action before Ms Smith’s death.

He said there had been no complaints made to the commission and no incidents reported in relation to the 54-year-old’s care.

In terms of action against Ms Smith’s care provider, Integrity Care, Mr Robertson found that once the commission became aware of her death, it took steps in relation to the company.

“I have not identified any significant failings in the nature or timing of those steps,” he said.

-AAP