Guode said she was mentally disturbed after giving birth when she drove the family car into the lake killing the three youngest children.
She had filed an application for leave to appeal her 26-year sentence earlier this month. Her defense attorneys argued diminished capacity before the Court of Appeal. The said their client was mentally unbalanced after the birth of her last child. The court upheld the verdict, making her guilty of multiple counts of infanticide, the Herald Sun reported.
The mother-of-seven was sentenced to one year in jail for one year for infanticide,  22 years per murder and another six years for attempted murder
Her defense attorney, Julian McMahon described the penalty combination as ‘not harmonious’.
‘We say the public conscience would actually be shocked by the severity of the other sentences,’ Mr McMahon said.
The prosecution argued the sentencing judge took into account Guode’s mental state.
The motives behind the 38-year-old, who survived the Sudan war, killing some of her children, remains unknown.
In July 2016, police released a statement alleging that Guode had spoken about killing herself and her children the day of the murders.

The children’s father, Joseph Tito Manyang [right] leaves the Melbourne Supreme Court after Guode was sentenced to 26 years prison for killing three of their children

It was revealed at trial that she was in huge debt and had sent almost $100,000 to family in South Sudan since she moved to Australia in 2008. Her attorney Marcus Dempsey said she snapped as a result of  ‘accruing of pressures and stress’.
After the birth of Bol, Guode suffered from postnatal depression and received little support from her community. She had left her first husband after starting an affair with the father of the three children, Joseph Manyang, and had been largely isolated from the community because of it.
In June of 2016, a court heard an emergency hotline [000] call from the moment Guode drove into the lake. A witness could be heard in a recording saying: ‘I saw them just drive full bolt into the water.’

The prosecutors reportedly urged the sentencing judge take into account Guode’s mental state when she drove her SUV [photo], into water 

At the funeral: After the bodies of her children were pulled from the lake, the Guedo [in black], initially blamed a dizzy spell for causing her to lose control of the SUV, until it was proven that she had to make three turns of the wheel before driving at full speed into the water

But an investigator said the car was deliberately driven into the water. Several police re-enactments showed the car could not have drifted off the roadway, as Guode claimed.
The re-enactments also demonstrated a driver would need to turn the steering wheel three times to get into the water.

A key witness also testified that Guode believed witchcraft had caused the crash.
The mother-of-seven told the woman she thought she was under a ‘spell’ when she drove into Lake Gladman.
The woman said Guode believed her lover’s wife may have used a witch doctor against her. She also testified that she overheard Guode say she would ‘rather take her own life and that of the kids’ than see them live with her lover, Joseph Manyang, and his wife.
However, during Guode’s sentencing hearing Manyang said he believed it was an accident and has continued to visit Guode in prison.
He said she was a good mother who loved all her children.
But Guode wailed in court as Justice Lex Lasry outlined the difficult personal circumstances she had experienced in the years before she killed three youngest children by driving her SUV into a Wyndham Vale lake on 8 April 2015.

The water rose to the roof line of Guode’s vehicle in Lake Gladman, where she plunged the SUV into the water to kill her children