The teenager who fatally stabbed mum Emma Lovell in a Boxing Day home invasion will now walk free more than a year earlier than expected, after a court found his sentence was too harsh.

The man, 20, pleaded guilty to murdering the 41-year-old mother-of-two on Boxing Day in 2022, after breaking into her family’s home in North Lakes, Brisbane, about 11.30pm.

At the time, the then 17-year-old forced his way into the house with an accomplice and a fatal struggle then unfolded on the front lawn.

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At sentencing last year, Justice Tom Sullivan handed down a 14-year youth detention order, well above the usual 10-year maximum under Queensland’s youth justice laws.

He cited the teen’s “particularly heinous” conduct, which included stabbing Emma and her husband, Lee Lovell, and kicking Lee in the head after he was wounded.

“This offending was atrocious and would create outrage in the community,” Justice Sullivan said at the time.

In a decision handed down on Friday, Queensland’s Court of Appeal ruled in favour of the teen’s challenge, reducing the amount of time he will spend behind bars.

In his appeal, his lawyers claimed the judge erred by ruling the crime met the threshold for an extended sentence, and that not enough weight was given to the teen’s early guilty plea.

The three-judge panel found the sentence imposed was “manifestly excessive” given the offender’s age at the time and other mitigating factors, including his early guilty plea.

His original 14 years detention with an order to serve 70 per cent of that behind bars equated to nearly 10 years.

Following the successful appeal, he will now serve only 60 per cent before becoming eligible for supervised release.

This means he could be out of detention more than a year sooner than first ordered.

The decision has reignited public anger and frustration, especially among those closest to Emma, who was remembered as a devoted wife and mother.

Lee, who was also seriously injured in the attack, has previously spoken out about the devastation of losing Emma and the need for tougher consequences.

“I will never get my wife back,” he told 7NEWS outside court last year.

“We’ve been given a life sentence.”

At that time, the appeal had already left Lee and their two daughters, Kassie and Scarlett, devastated.

“So if they take that away, it’s like putting less value on Emma’s life,” Lee told 7NEWS back then.

The teen killer cannot be named due to his age at the time of the offence.

His co-accused also faced court but was not convicted of murder.

The Queensland government and the Lovell family have not yet commented on the Court of Appeal’s decision.

Emma was stabbed in the heart and died despite attempts to save her with open-heart surgery on the front lawn, she died at the scene.

During sentencing, Justice Sullivan revealed disturbing details, including how the offender had tried to stab them both multiple times and how the knife blade had broken due to the force used.

The court also learned the teen had a significant history of break-ins but had never been imprisoned before.

Emma’s death rocked the North Lakes community and led to renewed calls for action on youth crime, particularly after a string of violent incidents involving teens across the state.