Rachel Lee Reily appeared in the Supreme Court in Burnie on Tuesday afternoon for a sentencing hearing into the sex crimes she perpetrated on the child last year.

Crown prosecutor Claire Flockhart told the court Reily was a cleaner at her victim's school, though they met outside school and she began to communicate with him on social media in May 2021.

Defence lawyer Paul Sullivan said Reily had accepted she was going to be jailed, and would lose care of her seven-year-old son.

"In her own words she has ruined her own life, [and accepts] the impact she has caused upon the complainant," Mr Sullivan said.

Ms Flockhart detailed nine occasions of sexual behaviour, including penetrative sex, that formed the complaint.

She said that on each occasion the complainant did not wear a condom, and though Reily told police she was using contraceptive, the risk of spreading sexually transmitted diseases aggravated her offending.

Furthermore, Ms Flockhart said, on at least one occasion her victim's classmate of the same age saw her performing oral sex on the boy.

The prosecutor said that on another occasion, both Reily's son and the victim's 13-year-old friend were present in her home when she and the complainant engaged in sexual conduct.

Ms Flockhart said it was the state's case the nine specified acts "were part of an ongoing relationship", featuring "numerous occasions" of sexual intercourse across a four-month period.

"It is not asserted they happened without consent, but occurred between a 27-year-old and a 13-year-old," Ms Flockhart said.

The court heard the crimes were revealed when the victim's mother became suspicious and asked the boy's father to look at his phone, in which he found photos of the pair cuddling and notes detailing events in the relationship.

In a vulnerable witness interview with police in October, the boy disclosed details of the abuse.

Defence lawyer Paul Sullivan told the court his client believed she was in love with the child.

"At the time she believed she loved him and believed that was reciprocated," Mr Sullivan said.

He also submitted that it was the opinion of a mental health professional that his client's depression had "directly led" to the offending, and that she did not have any "paedophile sexual tendencies".

However, Justice Tamara Jago questioned how the doctor could make an assessment, and "without evidence of a successful treatment regime", go on to assert Reily did not pose a risk of reoffending.

Ms Flockhart also disputed the submissions, and Mr Sullivan said he would seek further clarity from the doctor.

Justice Jago adjourned the matter for further submissions on May 18 and Reily's bail was continued until that date.