A teenager who said she wanted to murder a social care worker appeared annoyed when things did not go to plan, a court was told.
The 17-year-old told gardai it was "music to her ears" to hear the woman "scream and cry" while asking her to stop.
The teenager had previously told her guardian ad litem (GAL) that her ambition was to move to the US and achieve fame in the porn film industry.
At the time of the assault on May 1 last year, the teenager was sitting in the back of a car driven by the social care worker.
She lunged forward without warning and dug her nails into the woman's eyes. When she stopped the car, the teenager said: "I am going to kill you."
The girl wrapped her legs around the woman's head and chest and tore clumps of hair from her head. She also bit the woman's hand and scratched her face.
At the Garda station, the girl - who had been in care since she was 10 - said she had a list of people she wanted to assault.
She was subsequently sentenced to five months in detention.
The details of the assault were included in a written judgment by the Court of Appeal, which upheld a High Court ruling that the girl be detained on foot of a Special Care Order.
The original High Court decision, made in December, was appealed by the teenager.
Ms Justice Maire Whelan said the care order "was necessary and proportionate and was validly made".
In her 22,000-word judgement, published yesterday by the Courts Service, she said: "The degree of cruelty and dysfunctionality experienced by the girl during childhood was extraordinarily severe.
"The evidence of the impact on her welfare and development of this is overwhelming, and bears out the argument that she does require the special care proposed.
"There is every chance her welfare and development will benefit from the therapeutic care that is proposed."
Ms Justice Whelan said the girl "was born into a household of extreme depravity and domestic violence" and her parents were locked into what was described as "a sadomasochistic relationship".
A psychological report said the girl was physically and emotionally abused by her father and when she was old enough "the father recruited her to join him in the abuse of the mother".
A 2017 risk assessment of the girl found that the care provided by parents was absent, unreliable and cruel.
The father, who was described as "sadistic" and "cruel", forbade the mother from holding or soothing the girl when she cried.
The mother left the family home in 2010 when the girl was eight to stay in a women's refuge.
In 2012, after a violent attack on her mother, the girl was the subject of a care order and has remained in care ever since.
The girl's formal education concluded when she was 14.