When Daley arrived on the property, the victim's partner challenged him to a fight, not realising he was armed with the shotgun. When Daley snapped the barrel into place the other man recognised the sound and ran for cover, as Daley followed, trying to point the gun at him.
The other family members ran towards Walker-Dahlberg, who locked herself in the car. The family members began pounding on the window of the car, at which point Daley ran over and hit one of them with the butt of the gun.
"You turned the shotgun on [the victim] and shot it into her left leg," Justice Ellis said.
He then got into the car and fled the scene, firing once more out the back of vehicle and shattering a window of the house where another family member was.
The victim suffered "life-threatening injuries" which left her in hospital for months. Her leg was amputated above the knee.
"Her life has been permanently and horrifically affected by what you did that day," Justice Ellis said.
The victim had lost her children and her independence, she said.
"Your unnecessary, thoughtless and violent actions took those things from her."
Justice Ellis said Daley himself had a hard childhood, was abused by family and again in state care, and was "badly affected by the horrendous death of the little girl Lillybing," who was a member of his extended family.
Two-year-old Hinewaoriki Karaitiana-Matiaha - known as Lillybing - died after sustained physical abuse, leaving her with more than 90 bruises and abrasions on her small body.
She died when Daley was 12, Justice Ellis said.
"No one deserves a childhood like yours, Mr Daley, and only the very strongest are able to get past such an upbringing."
In court this morning, Daley was given the opportunity to apologise to the victim directly.
"I know I did wrong and I pretty much messed your life up, and I'm sorry for that," he said quietly as he rubbed his hands together.
"If I could take it back, I would."
Crown prosecutor Grant Burston told the judge Daley "saying that he feels terrible" was "too little too late", and the court should not give him a discount for remorse.
"He has wrecked her body and ruined her life."
"Mr Daley, at the time of the shooting, was a patched, high-ranking member of the Nomads criminal gang. He had been in jail for most of the previous 15 years for serious violent offending," Burston said.
Daley earlier pleaded guilty to aggravated burglary, causing grievous bodily harm with intent, and recklessly discharging a firearm.
Justice Ellis sentenced him to eight and a half years in prison.
Walker-Dahlberg appeared for sentencing later this morning on one charge of aggravated burglary.
The victim read out her impact statement during the second appearance, crying as she described how losing her leg had impacted her life.
"Sometimes I think it would be easier if Rex just aimed a bit higher and I was no longer here," she said.
The victim's children were removed from her custody because she could not provide a safe environment for them, she said.
She was in "constant pain" and was "totally reliant" on others.
"I will be always a burden on my family for the rest of my life."
The victim cannot be around fireworks, struggles to go out in public, and can't bring herself to wear her prosthetic "because it's not my leg".
Burston said Walker-Dahlberg fuelled Daley's descent into "kill mode" on the day of the attack, and still had high culpability.
Defence lawyer Mike Antunovic said Walker-Dahlberg was assaulted by the victim's partner before the incident, and that was the "catalyst for these events".
Justice Ellis allowed discounts to her sentence for remorse and time spent on restrictive bail.
She gave her an end sentence of three years in prison.
