A woman who attacked two strangers with an axe in a Sydney convenience store has had her jail term increased by five years.

Key points: The Court of Criminal Appeal imposed a 14-year sentence with a non-parole period of eight years

The Court of Criminal Appeal imposed a 14-year sentence with a non-parole period of eight years Her victims sustained serious head injuries after being struck by a 2kg axe

Her victims sustained serious head injuries after being struck by a 2kg axe Evie Amati said she did not have memory of the attack but recalled feelings of homicidal rage

Transgender woman Evie Amati, 27, was in January sentenced to nine years behind bars for the violent and unprovoked attack at the Enmore 7-Eleven in 2017.

The Crown appealed the leniency of the sentence and the Court of Criminal Appeal today set it aside and instead imposed a sentence of 14 years with a non-parole period of eight years.

It means her minimum jail term has nearly doubled and she will not be eligible for parole until January 2025.

Security camera vision captured Amati using a 2-kilogram axe to hit Ben Rimmer in the face and Sharon Hacker in the back of the head inside the store.

Evie Amati pleaded not guilty on mental health grounds. (Supplied: Facebook)

Mr Rimmer was buying a meat pie and Ms Hacker was buying milk.

Amati fractured Mr Rimmer's nose, eye socket and his cheekbone required reconstructive surgery, while the blow that hit Ms Hacker fractured her skull.

Medical staff said if Mr Rimmer's massive facial laceration was a millimetre above where it was, it could have had life-threatening consequences.

Outside court, Ms Hacker said the original sentence did not reflect the severity of the crime.

"Now at least there is some sense that there will be a chance for her to repair the emotional problems," she said.

"Although jail isn't the perfect solution, it's a better solution than being left in a life that you're not happy with."

Ms Hacker said the decision brought her closure and she felt like she could get on with her life.

Ms Hacker's thick dreadlocks cushioned the blow to her head, but she suffers from shooting pain down her arm and hand, chest pain and sleeping issues.

Victim Sharon Hacker outside court in August. (ABC News: Kathleen Calderwood)

Amati's lawyer had asked the court to reject the appeal by citing the progress she has made in custody and the antagonism she has suffered from female inmates due to her gender status.

But Acting Justice Carolyn Simpson said "a manifestly inadequate aggregate sentence was imposed for three very serious crimes".

"The sentence imposed significantly failed to reflect the criminality involved in the respondent's offences," she said in the judgement.

Amati did not remember attack

As well as the axe, Amati had a bright yellow kitchen knife in the back pocket of her shorts at the time of the attack.

She also swung the axe twice at another man, Shane Redwood, outside the 7-Eleven.

Mr Redwood took off his backpack and held it in front of him as a shield.

Amati pleaded not guilty to two counts of wounding with intent to murder and one count of attempted wounding.

She claimed she had a mental illness and was under the influence of hormone medication, cannabis, amphetamines and alcohol.

An hour before the attack Amati sent threatening messages to a woman she met on Tinder.

Amati said she did not have memory of the attack but recalled feelings of homicidal rage and said she heard a voice in her head telling her to "kill, kill".

In the original sentencing, Judge Mark Williams said the "chaos and disorder" in Amati's mind was a mitigating factor but did not minimise the seriousness of the attack.

The maximum penalty for each offence is 25 years imprisonment.