"It was video recorded by the respondent on the victim's phone," court documents state.
"He was repeatedly kicked, punched and threatened with weapons."
Duct tape was used to bind the 13-year-old's wrists and ankles, and cover his mouth.
According to court documents, the boy was punched in the groin and burned on the arm with a cigarette lighter while the 15-year-old girl filmed the assault on his phone.
The boy was then held to the ground while the girls used a pair of kitchen scissors to cut his hair and shave his eyebrows.
"He was further assaulted outside the house by being kneed in the chest and groin and struck on the head. The victim eventually escaped and ran to his parents' house," court documents revealed.
The 15-year-old girl and victim attended the same high school and were friends at the time of the offending. The court heard they had a group of mutual friends of similar ages.
The girl pleaded guilty at the earliest opportunity to a charge of take and detain with the intention of obtaining an advantage, assault occasioning actual bodily harm in company and common assault.
According to the NSW Court of Criminal Appeal judgment summary, the teenager had "shown genuine remorse and contrition", had changed schools in the interests of the victim to avoid future contact with him and cut ties with the co-offenders.
She was sentenced to a Community Corrections Order (CCO) of 18 months, expiring on August 17, 2022 and a conviction.
However, less than a month after convicting her, the judge "felt some concern about the appropriateness of having recorded a conviction" and withdrew it.
The girl appeared in the NSW Court of Criminal Appeal yesterday where the director of public prosecutions applied for the decision to be overturned.
The appeal court overturned the sentencing judge's decision to not record a conviction, stating it was necessary to the 18-month CCO she had been sentenced to.
