David Bain's future mother-in-law says she is "delighted" to welcome him to the family.
The former Dunedin man was convicted in 1995 of murdering his family and spent 13 years in jail before being he was acquitted in a 2009 retrial.
He is currently waiting to hear if he will be awarded compensation from the Government for his false imprisonment.
But in the meantime, the 40-year-old is in high spirits after his school teacher girlfriend Liz Davies agreed to marry him at the weekend.
Miss Davies is a primary school teacher at Cotswold School in the Christchurch suburb of Bishopdale.
The young teacher has been showing off her engagement ring to colleagues this week who have rallied round her since the news broke in the media today.
The Davies family have also welcomed the engagement.
Her mother Carolyn is a long-time Bain supporter, having visited him in prison and even billeting him during his second trial in the High Court in Christchurch, making his lunch every day.
She was baking at her Casebrook home, near where her daughter teaches, when approached for comment today.
She declined an invitation to speak about her daughter's engagement with the man she knows so well, saying: "It's very private."
However, she couldn't hide her happiness at the decision for the pair to tie the knot.
"We are all delighted," she said.
Today, parents picking up their kids from the leafy western suburban school were overwhelmingly supportive of Miss Davies.
Eight sets of parents - mums and dads - gave their backing to the engagement, with most saying Miss Davies was an exceptional teacher, but all refused to be identified.
One father summed up the feelings of most by saying, "I've got no problem with it at all. It's none of my business."
Online message boards were generally supportive of Bain and his future wife.
On a TradeMe community thread entitled, 'Got children at Cotswold school?', one poster reacted by saying: "What a dumb question. It's none of the parents business to be honest."
Two parents of Cotswold School children waded in with support for Miss Davies, who is also high up in the Canterbury Girl Guides regional management.
One wrote: "This is my son's teacher and I can assure you she is a wonderful teacher. Private life is private."
The school itself was tight-lipped over the news.
Teachers were posted at the gates after school today and told media to move on.
"At the school, we have no comment on personal matters," said principal Stephen Harrison.