Child welfare advocates have used coronal findings on the death of a four-year-old girl to renew their push for an overhaul of adoption rules across Australia.

South Australian Coroner Mark Johns handed down his findings into the death of Chloe Valentine on Thursday.

The child, who was the subject of repeated reports to the state's child protection body Families SA, died in 2012 of massive head injuries after her mother, Ashlee Polkinghorne and boyfriend Benjamin McPartland, repeatedly forced Chloe to ride and crash a 50kg motorcycle over three days.

The pair are serving four-year jail terms for manslaughter.

In his findings, the coroner recommended adoption be used in the child protection system.

Centre for Independent Studies research fellow Jeremy Sammut yesterday said Australia's history of forced adoptions was driving a fear of adoption that was "causing the irrational preservation of the family at all costs".

He called on the federal government to set national adoption targets to be met by each state to help drive change, but said all governments were wary of leading on any statements in support of domestic adoption.

"We've got to face up to the reality that our avoidance of adoption is harming children," he said.

He said in 2013-14 there were only 89 adoptions through care in Australia, 84 of which were in NSW.

Those had arisen after the state changed its legislation to accommodate for "permanency planning" and adoption.

Barnardos Australian chief executive Louise Voigt, who successfully lobbied for changes in adoption ruls in NSW, said she had written to Tony Abbott asking for the adoption of children in care to be placed on the Council of Australia Governments agenda but nothing had happened.

She said she felt as though she was repeatedly coming up against a brick wall.

"Adoption is not just for children, it's for life," Ms Voigt said.

Children are in need of longterm, consistent, loving relationships to rebuild their lives but in every state in Australia they are
being placed in a foster care system which is very variable.”

Families First MP Robert Brokenshire said the state government needed to go further on adoptions.

Only one local child had been adopted in South Australia in the past year, despite a significant number of people who desperately
wanted to adopt, he said.

South Australian Opposition Leader Steven Marshall said he would support an increase in the number of children being adopted.

“We certainly support increases in adoption” Mr Marshall said.

“I think we need to deal with it in a responsible way ... but we can’t just say we are going to do nothing.”

Child Protection Reform Minister John Rau yesterday said he would take preliminary responses to the coroner’s findings to cabinet
on Monday, but he said there were difficulties with adoption of children in care.

“Whatever way you look at it, a child being adopted in circumstances where the parents are alive is difficult and there’s not much we can do about that."

(This article was first published in the Weekend Australian on 11 April, 2015 and was written by Rebecca Puddy. Additional reporting Sarah Elks.)