She said a sole parent on the DPB with one child aged under 8 in Australia received about $390 a week in welfare payments - $100 more than in New Zealand - and also got child tax credits of about $200 a week.
Prime Minister John Key and Social Development Minister Paula Bennett have ruled out extending the credits, saying they were important incentives for parents to get into work.
Labour Party social development spokeswoman Jacinda Ardern said the poll results showed that voters believed that something had to be done about child poverty.
She said Labour was reconsidering its 2011 policy of extending the tax credit to beneficiary families, saying it was also looking at whether there were better ways to address child poverty.
Labour set up Working for Families in 2006 and reserved the tax credits for working parents as an incentive for people to get work.
The Green Party supports extending the tax credits to beneficiaries. Co-leader Metiria Turei's private member's bill to universalise the tax credit was defeated last year.
Jonathan Boston, professor of public policy at Victoria University, said the poll showed opinion was divided on the tax credit, but there was no easy way to address the income issue faced by parents on benefits.
Professor Boston co-chaired the Children Commissioner's expert advisory panel on child poverty, and said the panel was divided on the issue of the in-work tax credit.