Kelly Kirk's partner was shot dead by her daughter Daryl Kirk last February.
A jury at the High Court in Wellington found Kirk guilty of manslaughter when she admitted shooting Adam Watkins at their home in Lower Hutt, but claimed it was in self defence.
Mother Kelly Kirk however says she feels responsible for her daughter's actions.
"What's abnormal to some people was normal in our house ... Some of the violence and stuff like that, it wasn't the huge deal it would be in other people's homes," she told Fairfax.
Kelly Kirk's past included a violent relationship with now double-murderer Graeme Burton.
In 1992, at aged 15, Ms Kirk was out night-clubbing in Wellington with then-boyfriend Burton when he killed a man.
After urinating on the floor of club The Carpark, he stabbed the club's light technician Paul Anderson, Fairfax reported.
Mr Anderson died of blood loss.
She said Burton also chained her up to a bed and left her for two days.
His volatile behaviour didn't stop there, he threatened to kill her and her family if she ever left him.
When he was serving his sentence at Rimutaka prison, she broke it off with him.
Ms Kirk said she received threatening letters from him and when he escaped prison she went into hiding with her children, Fairfax reported.
Burton went on to kill father-of-two Karl Kuchenbecker in 2007.
Ms Kirk was now in a relationship with murder victim Karla Cardno's father, Gary Duffin.
Karla was 13 when she was snatched in Taita, Lower Hutt, on her way home from school in 1989 by Paul Dally.
She was raped, beaten and murdered on the Pencarrow coast, Fairfax reported.
Ms Kirk said she had been locked up 13 times and spent two decades on and off morphine, Fairfax reported.
The High Court heard yesterday, Adam Watkins was angry and had a meat cleaver, before Daryl Kirk fired six shots at him, hitting him three times.
The jury had the option of finding Kirk guilty of murder, but decided on the lesser charge.