The woman delivered a powerful victim impact statement in the ACT Supreme Court on Monday during sentencing proceedings for the now former teacher, Lee Brown.

In an unusual set of circumstances, Brown has already served three months in a NSW jail for sexual offences involving the same victim, who was her student at Yass High School.

Brown was released on parole two years ago and subsequently charged in the ACT with one count of engaging in sexual intercourse without consent.

The 61-year-old pleaded guilty earlier this year, admitting that she had kissed the victim and performed oral sex on her in Canberra during school holidays in January 2007.

On Monday, the victim told Justice John Burns she had never had sex before that incident, which took place in a shed behind the Higgins house Brown lived in at the time.

She said Brown, who she had trusted, had taken advantage of their bond for her own sexual gratification.

"My first experience of sex was sexual abuse," the victim said.

"[Brown] told me that I had obviously wanted it to happen."

The victim said that after the incident, Brown had urged her not to tell anyone about it.

This caused her to believe it was somehow her fault, and to carry around feelings of deep shame and disgust at her own body and the idea of intimacy.

She said she withdrew from friends and family and did not speak of what had happened for three years, before opening up to a psychologist who diagnosed her with post-traumatic stress disorder.

More than a decade later, she said, Brown's offending still haunted her through flashbacks.

"I still feel helpless and alone again, like I'm taken right back into Ms Brown's shed," the victim said.

"Thirteen years ago, my English and drama teacher decided she wanted to use my body for her own pleasure ... and for 13 years I have been the one who has had to pay the price for that."

Now, the victim said, the time had come for Brown to pay.

Brown's lawyer, Charlene Harris, urged Justice Burns to impose a non-custodial sentence.

Ms Harris noted that Brown had made frank admissions to police in NSW and the ACT about her offending.

She also said experts who had assessed Brown agreed she was remorseful, and that further time behind bars would likely just exacerbate Brown's feelings of self-loathing and act as a barrier to her seeking professional help.

Ms Harris told the court Brown's moral culpability was reduced by a number of mental health issues, which had come to a head in something of a personal crisis around the time of offending.

"This is an otherwise good person who exercised terrible judgement," Ms Harris said.

Crown prosecutor Sofia Janackovic said a jail sentence was clearly warranted, but whether it should be served by way of full-time imprisonment or in the community was a matter for the court.

Ms Janackovic stressed the seriousness of the offence, saying the victim had been entitled to feel safe with someone who had taught her "since day dot" in high school.

"This is a case that involves an egregious breach of trust," she said.

"That night in the shed, the offender took advantage of the victim's trust by taking away her first ever sexual experience.

"She effectively marked it as a moment of abuse."

The prosecutor said there was a 31-year age gap between Brown and the victim, as well as the obvious power imbalance, and Brown had known what she was doing was wrong.

Despite this, Brown had let her need for physical connection take priority over the victim's welfare.

"[Brown] wasn't operating under any delusion that it was fine," Ms Janackovic said.

Justice Burns said he would sentence Brown next Monday morning.