Kathy Mackay spoke after Dimple Scaife won a 12 month reduction in the period she must serve in prison, before she is eligible for parole, for murdering 18-year-old Jake Mackay.
Scaife, who had a son with Mr Mackay, stabbed him in the chest with a kitchen knife in Fosse Road South, West End, Leicester, in December 2006. She was told she would serve at least 12 years before she could be considered for release.
However, appeal judges in London have cut the 25-year-old’s minimum term by 12 months because of the “exceptional” progress she has made in prison and the remorse she now expresses.
The ruling means Scaife, formerly of Bede Island, Leicester, will be able to apply for parole in December 2017.
Jake’s mother, Kathy Mackay, said: “The 12 year minimum sentence was an insult, but we had come to terms with that. So it’s difficult to put into words how upset I am that she has had a year taken off that. Taking away someone’s life is the worst crime possible. I am just so disappointed with the justice system. This is no deterrent.”