And to make matters worse, 10 minutes after arriving at their Levin home, Timmer-Arends opened a letter stating Michael Zimmerman, Windley's co-offender, would also be up for parole this year.
"Four years is not long enough, they left my son to die."
She said they would continue attending the hearings because it was the "last thing she could do for Michael".
The Parole Board's decision states Windley committed a deplorable act when he went with his two co-offenders, Zimmerman and Stoyan Militch, to Valentine's rural address just outside of Levin.
They were seeking retribution over a stolen hard-drive and someone urinating on a toothbrush.
Windley and Zimmerman, both under the influence of drugs and alcohol, loaded a dog into their car and picked up Militch who took with him a sharpening steel. As they went to confront Valentine's fiance, Elizabeth Ham, a scuffle ensued and Militch fatally stabbed Valentine in the chest.
The three men left Valentine on the front lawn and fled.
The decision states Windley has completed a number of rehabilitative programmes and shows some insight into his offending. His parole comes with various conditions including being banned from travelling any further south than Taupo, attending alcohol and drug programmes and remaining on a curfew of 10pm-6am until May this year.
Timmer-Arends said these conditions offered no comfort to the family who were still paying a heavy price.
"We've always said we know this wasn't manslaughter. Four years for Michael's life, ask yourself would any parent be happy with this?"
She vowed to continue fighting for justice for her own family and for other victims.
"I do this to keep others safe too. I believe these guys are capable of reoffending, it's just a matter of when."