The Crown is appealing the 12-year prison sentence of Whanganui grandmother Lorraine Smith.
In May 2019 Smith pleaded guilty to murdering her granddaughter, 13-year-old Kalis Manaia Smith.
In the High Court at Wellington in August 2019 Justice Francis Cooke sentenced her to 12 years' prison. She is not eligible for parole for six years.
On March 15, at a Niblett St property, Smith strangled her granddaughter. Soon after that she dialled 111 and admitted the killing.
In August the court heard that Smith was caring for a handicapped son and three grandchildren. She was 59 and had her own mental health issues. She was suffering from "carer burnout" at the time of the offending.
People convicted of murder are usually sentenced to prison for life, with a minimum non-parole period of 10 years.
At the time of the sentencing Smith's lawyer, Peter Brosnahan, argued that such a sentence would be "manifestly unjust" for a woman who had dedicated her life to looking after her family.
The Crown case will be heard in the Court of Appeal.