A carer who told a Canberra boy with an intellectual disability that sexual acts between them would be "their little secret" will not spend time behind bars.

Key points: The woman will serve her sentence in the community through an intensive corrections order

The woman will serve her sentence in the community through an intensive corrections order The 15-year-old victim struggles with guilt and fear since the abuse

The 15-year-old victim struggles with guilt and fear since the abuse The offender was found "morally culpable" but spared jail due to her own history of childhood abuse

The 28-year-old woman has been placed on an intensive corrections order by the ACT Supreme Court, after she pleaded guilty to an act of indecency and sexual assault.

She was spared the more severe sentence of jail time due to her own background as a victim of abuse.

Offender had no qualifications as a carer

The court heard the woman started out working for the agency — which supplied carers for home help — as a cleaner.

She had no qualifications, but was later elevated to the position of casual support worker in 2018.

It was while working in that role that she was asked to look after the victim, a 15-year-old boy, for an afternoon at short notice because his regular support worker was not available.

The court heard there was a conversation between the pair when the boy asked "Do you have a big vagina?"

The offender replied, "Do you have a big penis? Don't answer that!"

The court heard she committed the offenses of indecency and sexual assault later, as the pair watched a movie together.

The woman warned the victim not to tell anyone, saying it was "their little secret", but the boy eventually told his mother, who had become alarmed by his change in behaviour.

His mother told the court he held a toy gun to his head and said, "I hate my life, I want to die."

She said when she asked why he said, "I don't want to tell you because I'm scared I will get into trouble, it's really bad."

"I don't want to go to jail."

The crime was reported when the mother rang police that evening.

'Morally culpable': Court hears of woman's background of abuse

Chief Justice Murrell referenced the woman's childhood of abuse by her father. ( ABC News: Margaret Burin )

Chief Justice Helen Murrell noted that since the incident the boy had struggled with feelings of fear and guilt as well as embarrassment and confusion.

"Because of his disability, it has been more difficult for him to process and understand what occurred," Chief Justice Murrell said.

She also acknowledged his mother's fears that he could be at risk of manipulation by carers and others because of his guilt and confusion.

"She too has lost confidence in the disability sector, which adds to the already great stress of raising a disabled child," she said.

But Chief Justice Murrell said she also had to take into account the woman's deprived upbringing, noting the extreme neglect, bullying and physical and sexual abuse inflicted by her father when she was a child.

The evidence was backed up by the woman's aunt who gave evidence.

Chief Justice Murrell said she had also considered evidence presented to the court by a psychiatrist, summarising the effects of childhood abuse for both men and women.

"For males, the link between severe trauma and sexual offending is far weaker," she said.

"For females, it is often the case that sexual offending is related to emotional stress and dysregulation, and a lack of understanding of appropriate boundaries, particularly in circumstances where someone has displayed affection towards them."

Chief Justice Murrell said the women had expressed some insight into why the offences had occurred, "referring to her impulsivity and response to apparent interest in her by another person".

The Chief Justice also considered that the woman, who displayed a low average cognitive ability, had expressed remorse for the crime, writing a letter to the victim's family in which she acknowledged she had been out of her depth in agreeing to look after him.

But in sentencing Chief Justice Murrell said the woman would have to take responsibility for her actions.

"Although ... the offences were part of an isolated episode of impulsive conduct that was not initiated by the offender herself, she remains morally culpable," she said.

The woman will serve 22 months in the community, via an intensive corrections order, rather than in full-time custody.