"I wanted to calm her down," the woman said.
Her intervention, though, had the opposite outcome.
Walker pushed her to the ground, causing the woman to strike her head on the pavement.
They struggled before the victim ran off to her nearby home.
Walker followed.
Finding her locked in the bathroom, the defendant - "enraged" - began kicking the door repeatedly.
Her blows were of such force and persistence she smashed a large hole.
When Walker wandered away, the victim took the opportunity to bolt out of her temporary refuge and call police.
With more loud noises coming from the house, the woman re-entered to find Walker kicking a bedroom door.
Again, her confrontation only provoked the defendant further.
Walker grabbed her friend by the throat and slammed her head into a door several times.
The struggle continued in an adjoining bathroom as the duo wrestled on the vinyl floor.
"During this the defendant grabbed hold of the victim's hair and pulled resulting in large clumps pulled out," a police summary said.
Hearing the furore, the victim's flatmate came in and tried to talk to Walker, but she was in no mood for conversation.
She punched the woman, sending her backwards and causing her to hit her arm on a dresser.
Walker's arrest shortly afterwards provided little relief for the two flatmates.
The first was left with severe concussion and the court heard it was eight months before she returned to work because of the constant dizziness and nausea.
"When I tried to sleep, all I saw was Kellie's face," she said.
"Even when I did, I had nightmares about the incident."
The victim reached the point where she was terrified to leave her home and simultaneously scared to be living where the violent episode took place.
The second victim, who sustained ligament damage to her elbow, said she was managing a retail store at the time and had to work despite the constant pain.
She broke down in tears as she recalled the weeks of sleeplessness and hearing her flatmate crying during the night.
Defence counsel Jim Takas said Walker was remorseful.
But Judge Turner interjected.
The defendant claimed her violence had been "self-defence" and she continued to deny the assault on the second woman.
"With regards to remorse, I see none," the judge said.
It was inexplicable, he said, why a young woman with no previous convictions would act in such an extreme manner.
Walker was sentenced to four months' home detention and 100 hours' community work.
She was ordered to pay the first victim $1859, the second $600, as well as $380 for the damaged door.
