The Sydney woman went on to become Australia's first National Children's Commissioner, in a career driven by the firsthand knowledge of what it is like to be a vulnerable kid.

Ms Mitchell has now achieved another career high, being recognised in the Australia Day honours for her significant service to children, human rights, and wellbeing initiatives.

She is thrilled but shocked to join the likes of Olympic champion Ian Thorpe, award-winning actress Rachel Griffiths, and a host of politicians and industry and community leaders as a Member (AM) of the Order of Australia.

"I thought it was a mistake," she told AAP with a laugh.

Ms Mitchell has spent her career quietly going about the work of protecting and uplifting children who were born at a disadvantage.

"My mum was a single parent with hardly any help around her and she did it pretty tough ... we moved 14 times before I was 17," she said.

"I've always had an appreciation for those people who are poor or who are disadvantaged."

Ms Mitchell has been the chief executive of the Australian Council of Social Services and held senior public service roles in the areas of child protection and disability in two states.

She's also sat on a number of boards, led the development of policy responses to the child sexual abuse royal commission, and published six statutory reports on child rights issues.

However it is her work as the first National Children's Commissioner, putting a focus on children's rights for the first time at a national level, that she is most proud of.

While Ms Mitchell has seen huge advances in children's rights in her career, today's youth are under pressure in ways unlike those experienced by generations before.

"Knowing the awful things that can happen to children is a pretty hard thing to swallow."

"One of the hardest things is knowing that in trying to protect children, you don't always get the best outcomes for them and they get swept up into systems that do them even more harm."

Compounded by the threats posed by technology, the COVID-19 pandemic, increasing domestic violence and struggling child protection systems, there's still a long way to go in securing children's rights in Australia.

Keeping her going, however, is the pride she knows her late mother would feel of what she made of her rocky upbringing.

"She would probably be a bit emotional about this."

"She'd be proud as punch. She'd be over the moon."

Australian Associated Press