St Andrew's Cathedral School: Details emerge about the death of a teenage girl after the Sydney private school was rocked by the murder of Lilie James

A 14-year-old girl who attended the Sydney private school where Lilie James was violently murdered has tragically died in a quad bike accident.

Peggy Richards, who was about to start year 10 at St Andrew's Cathedral School, died after 5pm on January 8 at a rural estate in Goolhi, northern NSW.

NSW Police confirmed the schoolgirl was the passenger of a UTV quad bike – which is larger than a regular ATV and designed to tow heavier loads – when it rolled into a body of water.

Paramedics attempted to revive Ms Richards but she died at the scene.

The driver, a 50-year-old man, was taken to Gunnedah Hospital for mandatory tests.

The school's principal, Dr Julie McGonigle, told parents that Mrs Richards had died in a 'fatal farm accident' in an email sent during the summer holidays.

Fourteen-year-old Peggy Richards studied at St Andrew's (pictured), where Mrs James was murdered. The teenager died in a quad bike accident during the summer holidays

Dr. McGonigle described Peggy as a talented design student who was “friends with everyone.”

“We are aware that this news will come as a shock and cause sadness and anxiety,” the senior teacher wrote.

“Peggy will be greatly missed. She was universally loved by her colleagues, and the staff who knew her best said, “Peggy had such a good heart.”

“She also had a depth of insight far beyond her years. Maybe that's why she was so strongly driven towards a future in design.'

It was the second tragedy to rock the school within three months after 21-year-old Mrs James was beaten to death by hockey coach Paul Thijssen, 24, in the gymnasium toilets.

It is understood the pair had a brief relationship for five weeks before she ended it.

Thijssen had made an appointment with her in the school gym, where he was preparing desks for the HSC exams.

Peggy Richards was a passenger on a UTV quad bike (pictured) when it rolled into a body of water

Ms Richards was at a property in Goolhi, northern NSW (photo of Goolhi is pictured)

The school's internal CCTV cameras captured both Ms James and Thijssen entering the gym's bathroom after 6pm, but only him leaving two hours later.

Police believe Thijssen took his murder weapon to the white Lexus he had borrowed or rented and drove from the school to Vaucluse in Sydney's eastern suburbs, arriving at 8.47pm.

Thijssen threw the hammer away at Vaucluse and, after calling Triple-0 to report his crime, jumped off the cliff at Diamond Bay Reserve.

A trader working on a boardwalk over the cliff above Diamond Bay found Thijssen's body wedged in the rocks below.

The death of Peggy Richards is being investigated by the Crash Investigation Unit. A report will be prepared for the coroner.

Do you know more? Email charlotte.karp@mailonline.com