Mlinac found children of prisoners' struggle with anxiety, bullying at school and grief over losing a parent, while the family suffers from the loss of income.
Those children had higher dropout rates for school and employment, over-representation in the criminal justice system, and there were detrimental effects to their health and wellbeing.
An estimated 23,000 children in New Zealand are affected by a parent in prison.
"It's a huge, huge list of what goes on in a child's life," Mlinac told the Herald.
"You've got the labels, the stigma, you've got problems at school. Even the fact of losing a parent to imprisonment is extreme."
Helen was living with her fiance, his two daughters and her daughter, all aged under 8, when he was sentenced to nine months in prison for assault in 2010.
The household income had gone down, but expenses increased.
Helen was able to go on a benefit for herself and her daughter but could not get any financial assistance for her partner's children for six weeks. She said Work and Income eventually allowed her to add the other children to her benefit and backpaid her.
"It was a ridiculous catch-22. I couldn't get the DPB for them because they were nothing to me, but I couldn't get the unsupported child allowance because they were my partner's children."
Helen also supported her partner while he was in jail. She sent him $50 a week for phone cards and cigarettes. It used to cost $1/minute for him to call home.
But the hardest part was helping the kids cope.
"It was as birthdays came and he wasn't there, over Christmas as well. They had to do all of that without him."
They would speak to him on the phone but his phone card would often run out a few minutes into the conversation. Helen tried to take the children for frequent visits when they could get transport.
"It's scary to start with. There's a little playroom but he's here in his orange jumpsuit and the little round tables are bolted to the floor. It's quite sterile and intimidating."
She said her ex-partner tried to pressure her into smuggling him drugs as he could sell them in prison. She never did but he talked about it so loudly that her house got raided and she was strip-searched once when she came to visit him.
"I had to go into the bathroom, strip naked, squat down and cough.
"There was nothing to find, but it sucked."
Helen said more contact, especially for the kids, would help. If telephone calls were a similar price to the outside and visiting hours more flexible it would help ease the emotional punishment on the family.
A Department of Corrections spokesperson confirmed that national calls were $1/minute in 2010, that rate was dropped to 40c/minute in 2012. The spokesperson said they are still looking into whether Helen was strip-searched or not.
Ministry of Social Development spokesperson John Allen confirmed that Helen was not paid a benefit for her partner's children for six weeks as it was unclear who would have care of those children.
"It took six weeks for us to get a lawyer's letter to confirm [Helen] was formally caring for them while her partner served his time, at which point we backdated the payments."
