Monica Elizabeth Young, 24, was due to face a seven-day trial in September 2021 after she was accused of meeting the student at his workplace and other locations in mid-2020.

But on Tuesday in Sydney's Downing Centre District Court she entered into a new deal reducing 12 counts, which had included sexual touching and inciting a child, to just three on a fresh indictment.

Young responded: "Guilty Your Honour," to three charges of having sexual intercourse with a 14-year-old between June and July 2020, in aggravating circumstances as he was under her authority.

Young's barrister Margaret Cunneen asked for enough time before the next court date for treatment regimes "which hopefully Ms Young may be able to enter into before the inevitable".

Crown prosecutor Alexander Terracini agreed she could remain on bail and did not propose a detention order for the moment but said custody would be the only option.

Judge Kate Traill was told psychiatric and psychology reports would be prepared for the next appearance.

Following consultation with police and the victim, the sentence proceedings will be far more efficient if (Young) remains in the community for those reports to be collected, Mr Terracini said.

Young allegedly sent the boy lewd messages over Snapchat while CCTV footage was believed to show her moving his hand under a table towards her groin, a court was earlier told.

She had formally pleaded not guilty in February to five counts of aggravated sexual intercourse with the boy as well as to other sexual-related incidents.

At a Supreme Court bail hearing in August 2020, Young's lawyer argued she may have been foolish in her dealings but totally denied any sexual contact.

Young's bail was continued so she can seek help within the community before she is due back in court on June 24 for a sentencing hearing.

Australian Associated Press