FOUND: Teacher s tears after sexually assaulting student - You Need To See This

The 30-year-old pleaded guilty to sexual intercourse with a person between 17 and 18 years old under care and using a carriage service to solicit child abuse material.

She was supposed to be teaching the student when she had sex with him at a NSW school, crown prosecutor Sarah Beaumont told the court.

She pushed for Nguyen to be taken into custody, emphasising that students and parents are entitled to expect that trusted educators won't abuse their position.

"The offender exploited a special relationship," Ms Beaumont said.

A sentence of imprisonment was the only appropriate sentence for the offences and the breach of trust they involved, she told the court.

But Nguyen's lawyer argued the 30-year-old needs to be on bail to attend appointments for her mental health, which would be adversely impacted by a stint behind bars.

She has engaged in meaningful mental health treatment programs and made significant progress since being charged with the offences, the court was told.

Judge Anthony Colefax noted that progress would be halted if the teacher was taken into custody while awaiting sentencing.

He declined to grant the detention application, finding it was likely but not realistically inevitable that she would receive a full time jail term.

Nguyen also admitted to nine counts of sexually touching a person between 17 and 18 years old under special care, which will be taken into consideration when she is sentenced at a later date.

When the detention application was denied, the teacher - who wiped away tears throughout the proceedings - cried and embraced her family.

Nguyen will be sentenced on May 29.

1800 RESPECT (1800 737 732)

National Sexual Abuse and Redress Support Service 1800 211 028

Lifeline 13 11 14

Kids Helpline 1800 55 1800 (for people aged 5 to 25)