The woman's defence lawyer argued she had been failed by agencies, when she asked for help.
A ministerial inquiry recommending changes to better protect children has been released following the sentencing of the woman who "tortured'' her nine-year-old daughter.
Crown prosecutor Lorraine McDonald told the court today that some of the abuse "amounted to torture".
Bennett this afternoon released the ministerial inquiry, which looked at the girl's case, as well as other matters relating to the welfare and protection of children.
"This child was subjected to cruel and barbaric abuse from her own parents in an unusual case where the mother manipulated many into thinking she had her child's best interests at heart,'' Ms Bennett said.
The inquiry, which was conducted by former ombudsman Mel Smith, included 13 recommendations.
They included better information sharing, new Child Youth and Family workers for schools, mandatory reporting of abuse and neglect, urgent research on kinship care, and a new Child Protection Court.
The woman's husband has pleaded guilty to three charges of assaulting the girl, two of which involve the use of a vacuum cleaner pipe and a broomstick. He will be sentenced in February.
Judge Gibson said during the sentencing that he didn't accept the woman was completely without assistance, and nor was she entitled to a lower sentence because the child was difficult.
He said he had seen much victim-blaming from the mother, and little victim empathy.
Ms McDonald, who had sought the 10-year maximum for injuring with intent to injure for the woman, told the court earlier today that some of the abuse "amounted to torture".
"There was particular cruelty and the Crown submits this abuse carried on for many months."
She said the abuse was not only physical, but psychological and included writing on the girl's body the words "skank", "incest" and "mental f***er".
Ms McDonald read a victim impact statement to the court from the girl's 8-year-old brother.
He said he was disappointed when he heard his parents had pleaded guilty because he wanted to come to court to tell people what had happened.
He said he hoped his parents "stay where they are for a long time".
"There is nothing nice about my mum. I can't think of any good things. I can think of lots of bad things. She would tell me that someone was going to take me away."
The boy said his mother was "the worst" and used to beat him because he did not listen to her. He said on one night he had to stay outside the house.
"I had to watch my sister getting hurt sometimes."
He said that on one occasion he told some friends at school about the abuse. They told a teacher who told his mother and he was beaten again.
The boy said that when he had bruises he was not allowed to go to school.
The boy's parents were charged after police found his sister hiding in a cupboard in November last year. She was reportedly starving, dehydrated and covered in countless injuries.
According to the police summary of facts, the boy's sister was beaten with weapons and had her toenail ripped off with boiling water and salt put on the wound.
Ms McDonald said the toenail had not healed and she had scars on her body.
"Some of it did amount to torture."
She said the girl would need long-term counselling for the abuse.
The mother's lawyer, Lorraine Smith, told the court her client could not cope with her daughter's behaviour problems and was let down by Child Youth and Family.
She said the girl was sexually abused while in the care of Child Youth and Family and developed behavioral issues before being released back into the care of her mother.
She said the authorities had failed her client, despite the woman trying to get help for her troubled daughter and there were no support systems put in place.
"That little girl was a timebomb waiting to explode and was put back into the care of her mother."
She said that at one point her client wrote to the Prime Minister about her daughter's problems and received a letter from Social Development Minister Paula Bennett promising six additional counselling sessions and sporting programmes.
"Sports activities are not what this child needed."