Leah Stensholt, 43, a mother of six with three different men, went home covered in blood after the murder and told her eldest daughter, ‘‘I killed the f...ing witch’’.

Stensholt was jailed for 20 years with a non-parole period of 16 years after pleading guilty to murdering Carol McDonald, 65, at Moyston, near Ararat, on May 5 last year but applied for leave to appeal her sentence claiming it was manifestly excessive.

Court of Appeal Justice Robert Redlich on Friday rejected the application.

‘‘The murder - rightly characterised by the sentencing judge as ‘cruel, callous and vindictive’ - occurred in the context of a custody dispute in which the victim was not directly involved,’’ Justice Redlich said when finding the sentence was appropriate.

‘‘There had been no contact between the applicant (Stensholt) and the victim for some years prior to the murder.

‘‘Essentially, the victim was killed as a kind of punishment for her son, the applicant’s ex-partner, and as a result of accumulated resentment on the applicant’s part towards her ex-partner’s family.’’

Stensholt, who had had three children with Mrs McDonald’s son, Paul, before they separated in 2008, feared she was going to lose custody of their two youngest children.

She drank six or seven stubbies of full-strength beer with her new lover before driving to Mrs McDonald’s home at Moyston.

Stensholt knocked on the front door at about 9pm and told Mrs McDonald: “Open the door and we’ll come and have a cup of tea."

But when Mrs McDonald refused to let her in, Stensholt found an unlocked door before grabbing the great grandmother around the throat and forcing her down the hallway into the kitchen.

Mrs McDonald cried out ‘‘please don’t’’ and ‘‘what have I ever done?’’ as Stensholt told her ‘‘don’t f--k with me, you bloody evil bitch’’.

Stensholt stabbed Mrs McDonald once in the throat as she held her on the ground.

She returned home covered in blood and screamed, “I killed the f---ing witch".

"Nobody thought I would do it, but I did," Stensholt told her eldest daughter, Kasha. "F--k them, I hate the McDonalds.”

When Kasha asked her how she could have done it, Stensholt replied, “I slit her throat like a lamb”.

Stensholt then called Mrs McDonald’s son, Paul, and left a message for him, saying: “You’d better answer your phone, I’ve got some news for you. Answer.”

Stensholt called Paul again a short time later and told him: “I’ve just killed your f---ing mother and you’re next. I’m coming for you.”

The judge said Stensholt then taunted Paul by saying: “Ring your mother. You won’t get her, I’ve just killed her.”