Metiria Turei's daughter says she would have "been hungry" if her mother hadn't misled Work and Income (WINZ) in the early 1990s.
Ms Turei made the confession last weekend, while introducing the Green Party's new welfare policy.
She was a single mum in 1993, and lied to WINZ about her living conditions so her accommodation payment wouldn't be reduced. She says she did it to make ends meet while studying towards a law degree.
Response was mixed, with many backing Ms Turei because they too have experienced similar financial hardship, and others calling for her to be investigated or even resign from Parliament.
Piupiu Turei, 24, told NZME she would have gone hungry without the extra money Ms Turei's deception brought them.
"I think I would've been hungry. It definitely would have been much harder for us - more hoops for mum to jump through and less time for her to focus on study and caring for me."
She said she was proud of mother's achievements and honesty in admitting what she had done.
"No matter what, she was going to look after us, and if it was hard, it was okay because we would get through it together.
"She taught me how to survive, love and thrive no matter what situation you're in."
Supporters of Ms Turei took to social media to share their difficult experiences dealing with Work and Income under the hashtag #IAmMetiria.
Newshub reported on Friday allegations that Work and Income employees deliberately make it difficult for beneficiaries in order to reach monthly targets.