In a written decision, the parole board said it was satisfied Quinn would not represent an "undue risk" to the safety of the community on release.
"The offending is specific and there is no evidence of any behaviour outside the circumstances of this offending that would represent risk."
Sensible Sentencing Trust spokesman Garth McVicar yesterday slammed the decision to release Quinn.
"One of the purposes of sentencing is to send a deterrent to the wider community. Releasing Quinn [after serving a third of her sentence] fails to do that and instead makes the focus on her, not her victim, wider family or wider community, and that is wrong.
"New Zealand has a shocking level of child and elder abuse and if we are to ever rise above that, time served in prison will need to reflect the community's abhorrence."
Quinn was "well behaved" in prison, but was also "somewhat withdrawn and reclusive", an assessment stated.
She had no visitors and appeared to have "limited support" available to her.
The special conditions of her parole included undergoing a psychological assessment and any recommended counselling to the satisfaction of her probation officer, as well as not moving from her address without the written approval of the officer. She has to abide by these until November 15 next year.
During the trial, Detective Toni Leppien said Mrs Quinn told her she could not believe the state she had ended up in.
"There was one time during the interview where I held her hand and she said 'your hand is so warm. I can't remember the last time someone touched me'."
Quinn tried to explain her lack of care, claiming her mother did not like to be moved or touched because of the pain and wanted to remain independent. Quinn lived at the family home with her son and relied on her mother's pension for an income.
Judge Jonathan Down told the court he could not overlook how extensive the woman's wounds were. The "sense of neglect" had a "stunning" impact on Hawke's Bay Hospital staff, he said.
The hospital's chief medical officer, Dr John Gommans, said the elderly woman's condition was "something I've never seen".