SA woman who drowned daughter mentally ill

A mentally-ill woman thought she was protecting her two-year-old daughter when she drowned her in an Adelaide Hills dam after hitting her on the head with a metal drink bottle.

Justice John Sulan on Monday formally published the reasons for his December ruling that Catherine Anne Pallin was not guilty of murder, due to her being mentally incompetent at the time.

He also placed the 40-year-old, who has been on bail, on a community supervision order with conditions including ongoing psychiatric care.

The Supreme Court judge said Pallin should be allowed to continue to travel interstate to see her parents and brother who were part of her support network.

In his reasons, Justice Sulan said in the lead-up to the drowning, Pallin had a history of mental health incidents and hospital admissions.

She stopped taking her antipsychotic medication, "as she claimed it made her feel ill and did not fit with her lifestyle of `clean living'."

On July 17 2013, she drove her daughter Ayeesha Aqua Pallin to a dirt road near her Macclesfield home.

She recalled having thoughts of killing herself but did not want to die and "leave Ayeesha to experience the awful life".

She hit her with the bottle and walked into the dam, completely immersing her daughter in water.

Pallin told police she knew she had to do it to protect Ayeesha and "felt a huge amount of love" for her.

After hearing evidence from psychiatrists, the judge concluded Pallin was suffering from an acute psychotic episode at the time and did not know her conduct was wrong.

"She believed that her partner and others would inevitably harm the deceased and herself."

Pallin was clearly psychotic and delusional when she drowned Ayeesha, he said.

* Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14.