Maureen Quinn's granddaughter Trena Quinn told Hawke's Bay Today it was "devastating" to discover her aunt had neglected her nana.
Trena Quinn said whenever she asked to speak to her grandmother her aunt would refuse or say she was sleeping.
"If you banged on the door she [Joanne] would say she was calling the police.
"None of us could get in to see nana."
She said the windows to the home had been "nailed shut" by Joanne while the garden, once the pride of her nana, had become a jungle.
"If we knew what she was doing in there to nana we would have busted through that door anyway we could."
Trena Quinn first noticed the severity of her 82-year-old grandmother's condition when she visited her in hospital.
"It was shocking - I personally don't understand how a [daughter] could do that to her mother."
During Joanne Quinn's trial it was revealed she lived at the family home with her son and mother and relied on Maureen Quinn's pension for an income.
Severe neglect case prompts elder abuse warning
The case has prompted a warning not to turn a blind eye to elder abuse.
Age Concern urged anyone who believed an older person was being abused to call the group to get help.
The group's elder abuse and neglect prevention services national adviser Louise Collins said it was a tragic case of neglect, and no one should have to endure what Maureen Quinn did.
"This is indeed a tragic case. Every case of abuse is tragic. Unfortunately, Age Concern deals with many distressing cases of abuse and neglect."
Mrs Collins said Age Concern's abuse and neglect prevention services received more than 2000 referrals for cases of suspected abuse every year.
"Information obtained from Age Concern elder abuse and neglect prevention services indicate that the older a person is, and the more reliant they are on others for care and support, the more likely they are to be abused."
Prior to yesterday's verdict being handed down, Quinn was approached by another woman and slapped, before the woman, believed to be a family member, fled from the court and was pursued by security. She managed to escape the court house.
During his deliberations, Judge Jonathan Down said in the context of the case, nourishment, hydration and medical care were the necessaries of life.
Judge Down said the Crown argued Quinn clearly owed and had a duty to override the wishes of her mother and provide those necessaries of life.
"This is the sort of case that can give rise to the feelings of prejudice and sympathy," Judge Down said. "One only has to look at the photo evidence and listen to the medical witnesses.
"What I was struck by was a very broad and deep agreement by all the medical witnesses about the state and condition of [Maureen]."
He said all the medical evidence appeared reliable and consistent.
Judge Down said Maureen Quinn was severely dehydrated, severely malnourished and showed signs of severe neglect, while not being able to withdraw from her daughter's care.
In light of "compelling medical evidence", the judge reached an "inevitable conclusion".
Judge Down was struck by one moment when witness Detective Toni Leppien gave an account of holding hands with Maureen Quinn in hospital.
"Your hand is so warm. I can't remember the last time someone touched me," Maureen told the detective.
Judge Down said the 82-year-old was referring to the "warmth and comfort" that must have been missing from her home environment.
He had no doubt Maureen's life was in imminent danger and had she not been admitted to hospital on November 15, 2011 her death would have come at a much earlier stage.
"It was obvious to the defendant and to all, beyond any reasonable doubt, that much greater care was required."
Quinn was granted bail until sentencing on May 16.
- Additional reporting by APNZ
