Edmunds was 29 when her husband Glenn Cassidy fatally shot her ex-partner Michael Caposiena outside his Westmeadows home in March 2016.
Cassidy went to the unit armed with a single bullet and a plan - one Edmunds knew well after he told her, "you know what I'm going to do when you're away".
Cassidy had plotted the hit as early as December 2015 and put together a to-do list on his phone noting "one bullet" and "getting him alone".
He never stood trial for the killing, though, because in the final moments of Mr Caposiena's life, he pulled out a carving knife and fatally stabbed Cassidy in the torso.
Both men died at the home.
An investigation later revealed Edmunds goaded Cassidy into killing Mr Caposiena and was fed up with attending supervised visits with him so he could see their son.
The responsibility shifted to Edmunds and Mr Caposiena to organise future visits themselves the day before the killing, the Supreme Court of Victoria was told.
In sentencing on Tuesday, Judge Lex Lasry said it was his view the now 37-year-old Edmunds instigated planning for Mr Caposiena's murder - albeit with Cassidy as the not-reluctant executor of her wish.
She wanted the problem of the visits to disappear, wanted Mr Caposiena dead and told family members she wanted him out of her life.
Edmunds gave Cassidy Mr Caposiena's home address, drew a map, helped him with surveillance and fabricated a text message in an attempt to prove she was not implicated in his murder.
Ultimately, she tried to avoid an inconvenient dispute with homicidal violence, the judge said.
"The issues confronting you were so easily resolved without resorting to violence," Judge Lasry said.
He sentenced Edmunds to 26 years in prison.
She will be eligible for parole after 20 years.
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