Lindholm pleaded guilty to murder after enlisting her lover Torsten Trabert and another man, John Ryan, to kill Hawthorn gym owner Wayne Amey on December 10, 2013.

This was one day before Lindholm and Mr Amey were due in court to address a dispute they had over a farm they owned in Bittern.

Mr Amey's body was found in a crevice on Mount Korong, near Wedderburn, on December 18, 2013. 

The trio last week appealed their prison terms, arguing they were "manifestly excessive".

Lindholm is serving 25 years, Trabert 28 years and Ryan 31 years in prison for Mr Amey's murder.

Court of Appeal Justices Mark Weinberg, Simon Whelan and Phillip Priest unanimously dismissed Lindholm's right to challenge her sentence and refused Ryan and Torbert's appeals.

The judges said in a joint decision that Lindholm's sentence was comparable with other similar cases where people were motivated to kill because someone had taken legal action against them.

"It is difficult to overstate Lindholm's moral culpability for this crime. She pleaded guilty but the [sentencing] judge found that she was not remorseful..." they said.

"In our view, the sentence imposed upon her was a merciful one in the circumstances."

The judges said: "This was a truly terrible crime. Lindholm had tried to have Mr Amey killed for two years, including trying to persuade others to kill him for her.

"Trabert and Ryan callously, ruthlessly and violently carried out her wishes."

Lindholm had continued to arrange for Mr Amey to be murdered even after she was given a community corrections order for breaking into his apartment.

The judges said the sentencing judge had given her prior criminal history "markedly favourable" treatment.

Lindholm's lawyer, Scott Johns, had argued that her sentence was "unmistakably outside the range" available, and that the sentencing judge had not given enough weight to her guilty plea.

The judges dismissed Trabert and Ryan's respective appeals, saying that while Lindholm "might well be seen as having greater moral culpability than them", she had pleaded guilty, while they had maintained their innocence.

The two men were also "the ones who actually carried out the killing".

They said there was not enough of a difference between their prison terms and Lindholm's to warrant intervention.

Trabert and Ryan both argued that their sentences should be lowered because they had less responsibility for the murder than Lindholm.

Trabert's lawyer had claimed his client's motivation to kill was sex.

Ryan's lawyer said he had entered into the arrangement at a later stage, thinking they were going to beat Mr Amey for mistreating Lindholm.