The woman, who was 19 or 20 at the time of the offences, began a consensual sexual relationship with the girl while doing a practical teaching placement at a Lake Macquarie high school in 2006, a statement of facts said.

The relationship continued after the woman left the school.

She pleaded guilty to four counts of having sexual intercourse with a minor.

The case was adjourned in Newcastle Local Court yesterday so a pre-sentence report could be prepared.

The offender and the teenager knew each other before the offender began training at the school, the statement said.

The teenager invited the offender to watch her play sport one weekend and they later agreed to meet at night.

They met at the Edgeworth McDonald's car park and drove to the offender's home at Eleebana.

They went for a walk and kissed and cuddled before returning to the offender's home to have sex.

Two weeks later the teenager snuck out of her home and met the accused who had parked nearby.

They had sex in the backseat of the offender's car.

On another occasion the teenager went to the offender's home instead of school.

They had sex before the teenager took photos with her mobile phone of herself in bed with the offender.

The teenager introduced the offender as her girlfriend to her mother on her 16th birthday.

There was animosity between the teenager's family and the offender, but the pair continued to see each other.

The teenager's stepfather was looking for a video game console one night when he entered the teenager's bedroom and turned on the light and found the offender in bed with his stepdaughter.

The offender said she loved the teenager and had been sneaking into the house for about six months.

The teenager's family reported the relationship to police, but the teenager told detectives she and the offender did not have sex.

Police interviewed the teenager again last year and she admitted having sex before she was 16.