Yesterday her mother, Pauline Hoare, sought more time in the NSW Supreme Court to sue Far West Area Health Service for the nervous shock she suffered when she discovered what had happened to her 21-year-old daughter on December 9, 1994.

The statutory time limit to sue in NSW is three years.

Cousins Vester Allan Fernando and Brendan Fernando were both found guilty of the abduction, rape and murder by a Supreme Court jury in Dubbo.

Vester, who is serving a life sentence for the crime, also killed Brendan in jail in September 1999.

Ms Hoare's counsel, Geoffrey Graham, said his client had suffered "chronic, debilitating depression", insomnia and concentration problems as a result of her daughter's murder.

She had to leave her employment at Centrelink in 1997 because of her symptoms and had not returned to work, Mr Graham said.

"No one ever told her what her daughter's injuries were," he said.

"It was only at the committal (hearing) that she finds the horror of what the injuries were."

Ms Hoare first inquired about her right to sue over her psychological trauma in 1996 but a solicitor told her he did not want to pursue it, Mr Graham said.

She had asked another lawyer about her right to take legal action in 2001 and started proceedings soon after.

However, counsel for the hospital, David Nock, SC, said there was no evidence to prove whether Ms Hoare's nervous shock started after the murder or after her daughter's killers' legal proceedings had begun.

"It was at the committal hearing that she heard all the disturbing facts about her daughter's death," Mr Nock said.

"What we have to deal with is the question of causation."

But Mr Graham said it did not matter if her shock started after the murder or the trial - it was still from the same cause.

"It's all the one event," Mr Graham said.

Master Bryan Malpass has reserved his decision.