Frances Anne Phelps, also known as Faye, was found dead at her home on October 7 but police allege she was murdered several days before her body was located.
Her alleged killer can now be named as Elliot Alfred James Cameron, who is in his 70s and was "a mental health patient" at Hillmorton Hospital, the New Zealand Herald reported.
Until today, Cameron’s name, age and other details had been suppressed so he could not be identified.
The interim suppression order was lifted on Friday when he appeared in the High Court at Christchurch before Justice Jonathan Eaton, the Herald reported.
Eaton remanded Cameron in custody until his sentencing date on June 10.
Details of Cameron’s mental health history cannot be revealed, the Herald reported.
However, after he was arrested, Health New Zealand South Island deputy executive Martin Keogh issued a statement.
"I can confirm that a mental health patient was arrested at the Hillmorton campus ... and has appeared in court charged with murder,” he said.
"Our sincere condolences are with the family of the person who died.
"As the matter is currently before the courts, I am limited in what further comment I can make.
"However, I can assure the public that we are taking this incident extremely seriously and a full review will be undertaken."
Karen told the Herald her mother was a fit and healthy 83-year-old "homebody" who loved her home and garden.
She said her mother was born in Christchurch in 1941 and married Bill in 1965.
Cameron’s actions have had a "devastating" impact on her family, Karen said.
"It still feels surreal and it is hard to get our heads around what has happened,” she told the Herald.
"We miss mum terribly. Our lives are not the same any more. For example, whenever I go about my daily life, someone will inevitably say something. It’s not like a normal death where not everybody knows.
"People have also been talking about it. Not that I blame them, people are shocked and want answers and so it’s natural they will talk.
"But it has led to misinformation about her death circulating, which has been upsetting for those that knew her," Karen told the Herald.
She said there were many unanswered questions about her mother's death.
"She was a sweet, innocent lady. She didn't deserve that, nobody does."
Last year Karen told RNZ her mother was a kind and gentle soul who was treasured by everyone.
"It's obviously very difficult to have someone wrenched away from you so suddenly and unexpectedly in such circumstances. It feels like being in the middle of a movie, surreal and unbelievable," she said.
"It's had a wide-reaching effect with my mum having touched so many lives with her generous nature. Everyone is struggling to cope and understand how something so horrible could have happened to such a lovely person."
She said her mother gave a lot to her community and was a keen singer and actress with a strong Christian faith.
She had lived in the same house for 50 years with her husband Bill who died two years earlier.
