The Prime Minister is continuing to defend cutting the benefits of parents who fail drug tests - saying fewer than 10 families are affected.
Last week the Children's Commissioner Andrew Becroft urged the Prime Minister to "put children first" and reconsider her support for punitive drug sanctions for beneficiaries, especially those with kids.
"Children shouldn't be penalised for the actions of adults over which children have no control - I think it is unprincipled and as Children's Commissioner I would be derelict in my duty if I didn't say please reconsider," Judge Becroft told 1 NEWS.
But on Friday, Ms Ardern said it was important for the matter to be put in perspective.
"I would be loathe for there ever to be a perception that this is a widespread issue or a widespread problem," she said.
"We are talking literally about less than 10 families who are affected by sanctions when they have children, and in those cases no one ever loses their full benefit, that would not be right," Ms Ardern said.
Asked by 1 NEWS if the children in those 10 families were still being penalised, Ms Ardern responded: "They should never lose their full benefit but again this is an issue that effects a very small group."
"It is about mutual obligations though - the vast majority will never ever face a sanction for this issue, because the vast majority of course never engage in drug use."
She said for a "very, very small group" it was about obtaining help from Work and Income "so that we can give you the support that you need to support your family and also find employment....that does require being free from drugs".
Judge Becroft also told 1 NEWS last week that sanctions were not a solution for those in poverty.
"We've got to do better than this.
"Putting children genuinely first will mean that we don't make poverty worse for them."
In Opposition, Ms Ardern-the now Minister for Child Poverty Reduction, and the Labour Party repeatedly opposed the drug sanctions.
In 2013, the Labour MP Phil Twyford warned that cutting a parents' benefit by 50 per cent would "ultimately do severe damage to the child".
A small number of beneficiaries fail drugs test each year - in the year to June almost 40,000 people were referred for jobs that required a drugs test, with 114 failed tests.
Nearly two-thirds of those were sanctioned. Beneficiaries with children can have half of their benefit taken from them.