Benefit rates for families with children rose by $25 a week, the first time it had risen higher than inflation since 1972.
In Northland, 4417 people were on a solo-parent benefit as of March, with plenty more on other benefits.
Low-income working families would also get up to $24.50 extra a week from the Government.
Opposition parties and child poverty action groups said the plan did not go far enough.
Whangarei's Child Poverty Action Group convener Sherry Carne said the announcement would mean parents had to look for work while their children were left at home.
"I think the changes they've made were very punitive," Ms Carne said. "People who are wealthy don't have to leave their kids at home."
Whangarei CPAG member Ngaire Rae said it was "great" there had been a recognition of the inequalities many families face. One of the main things that concerned her was the requirement for parents to return to work two years earlier than before.
"Where are the 20-hour-a-week jobs that fit in with families?" Ms Rae said. "What happened to valuing the role of being a nurturer?"
Green Party co-leader Metiria Turei said the Budget was no solution to child poverty.
"John Key could have kept his promise to tackle child poverty, but he chose instead to do the bare minimum," she said. "Much of what National is giving to beneficiary families in one hand, will be taken away with the other."
Included in the child hardship package, to be implemented from April 2016, was an increase in the subsidy rate for low-income families from $4 an hour to $5 for up to 50 hours of childcare a week per child.
The Budget also included $59 million for vulnerable children interventions.
Last year, the Budget included $500 million over five years for a package that included free doctor visits and prescriptions for under-13s.