Margaret Dodds, photographed at an earlier court appearance, took pills at a Christchurch park and lingered to watch a boy.

Serial menace Margaret Mabel Dodds has admitted sitting in a Christchurch park and thinking about what she could do to a boy who was playing with a soccer ball.

Dodds says she wasn't loitering near the boy at Sydenham's Bradford Park in breach of her intensive supervision – she was there to swallow pills and take her own life.

When the police were alerted to the August 19 incident and arrived at the park, they had to call an ambulance because Dodds, 60, had taken the pills.

Dodds has achieved notoriety on social media for loitering around Christchurch parks and public places where she faces a sheaf of trespass orders.

Bradford Park is one of the few places where no trespass order applies to her, but her intensive supervision order bars her from any contact with children.

She has served jail time for her repeated offending with trespasses and assaults, and this offence occurred not long after her latest release.

Dodds, who normally lives at Princess Margaret Hospital's Seager Clinic, was taken to hospital after her overdose on painkillers she had bought at a Beckenham supermarket, her judge-alone trial before Judge Brian Callaghan in the Christchurch District Court was told today.

Interviewed later, she admitted she had sat on a bench in the park and had watched the boy playing with a ball. She said she had been "thinking about what she could do to the boy", according to the probation officer who interviewed her.

A woman going through the park with her own children recognised Dodds from warnings on social media. She told the court she spoke to Dodds. She told the boy it was not safe to remain at the park and he should go home because the woman was "not kind to children".

She alerted the police.

Dodds denied the charge of breaching a condition of her intensive supervision by lingering around the boy in the park.

Defence counsel Kirsty May argued that "to watch is not to linger". She said Dodds had gone to the park to commit suicide and was not lingering there because the boy was there.

However, Judge Callaghan found the charge proved after the one-day hearing. He found Dodds was "lingering for the purpose of keeping an eye on the boy, and was considering what she might do to him".

Prosecutor Courtney Martyn said the Crown wanted Dodds be jailed for the offence, but it did not oppose bail pending sentencing, which has been set for March 23.

Judge Callaghan granted bail and asked for a pre-sentence report to consider Dodds' suitability for home or community detention under which she would be electronically monitored.