Judge Gilbert delivered his verdicts in the judge-alone trial, two days after the conclusion of the evidence. He granted interim name suppression to protect the identity of the boys.
The stepmother and the boys' father separated soon after a final incident in which she has also been convicted of assaulting the father.
The stepmother denied 12 charges of assaulting the boys with a weapon, a charge of assaulting her ex-husband with a weapon, and a charge of assaulting him as a family member.
The defence challenged the accounts of the boys, now teenagers, and their father, about violence inflicted over a period of years.
The boys told of years of regular beatings with a metal kitchen spatula or wooden spoon, which would cause injuries that made their buttocks bleed. They said the assaults - for offences such as for making a mess, having a water fight, failing to eat their school lunch, or returning to school when they could not find their stepmother at home - went on for about six years.
But over that period, little had been seen of injuries or marks, explained away when they were seen, as childhood injuries from play and sports, or as a reaction to a milk allergy. And the boys said they had not reported the violence to their father earlier because they said they were scared and intimidated by the stepmother. The trial heard no evidence of bloody marks being seen on their underwear or pants.
The complaints from the boys emerged in a conversation with their mother, after a violent dinner-time incident where they alleged the stepmother had attacked their father, in an incident that sent a dinner plate flying and the steak knife he was holding at the time may have caused injuries to his face. The father said the stepmother had grabbed his hand and forced his hand towards his face. The couple separated after that.
Judge Gilbert found that the woman had intentionally thrust the husband's hand, holding a steak knife, towards his face at least twice, causing two cuts and a scratch on his glasses, and then punched him at least once before he managed to get control of her.
He said the boys' accounts of the assaults were congruent, "but not so strikingly similar as to make me think that the pair of them had fitted up a story". Neither appeared to "speak to a script".
"I found them both to be very good witnesses," he said. He later described them as "compelling witnesses".
The marriage of the father and stepmother was "imploding" during some of the period covered by the trial. If the boys had been lying, it was much more likely that they would have first have made their complaints to their father as a show of support to him. In fact, they had first made their allegations to their mother, years after the abuse had ceased.
There had been earlier opportunities for the boys to complain to adults, but it was well established that there were very good reasons why complainants, particularly children, might delay complaining about abuse, or never complain.
He did not accept it was inevitable the boys' father, or mother who had them every second weekend, would have noticed blood on their clothing. The abuse was likely to cause only small cuts and likely small amounts of blood. The stepmother did most of the domestic duties at their house and their father spoke of "gathering up clothes in a bundle" when he did the laundry.
"It also has to be borne in mind that the boys were frightened, and perhaps, embarrassed, by what was happening to them," the judge said.
Courtney Martyn appeared for the Crown; Craig Ruane appeared as defence counsel for the woman.