But defence lawyers argue the mother of Mary Ivanisevic, 45, stabbed herself and told a jury there was "no doubt" the woman, who was terminally ill and has since died, would give that same evidence in court were she still alive.

Ivanisevic is on trial in the ACT Supreme Court, fighting an attempted murder charge after her mother was found laying on the floor of her Curtin home, still attached to an oxygen machine and with a gash to her chest, in December 2015.

The Crown alleges the pair's relationship was volatile and Ivanisevic stabbed her mother before she drove to a nearby service station to create a false alibi.

In his closing address to the jury, prosecutor Anthony Williamson said the stabbing would have been "a particularly violent way" for "a frail old lady" to kill herself.

"This is a woman who was so sick she couldn't attend to the most basic of tasks."

The mother, who had end-stage lung disease, lived in fear of the accused, who had bullied and assaulted her in the lead up to the incident, he said.

"I would suggest to you that the accused has stabbed her mother out of anger and, or, frustration."

He pointed to evidence Ivanisevic told her mother to admit she stabbed herself as she recorded he comments on mobile phone and while a neighbour offered first aid, saying: "Who does that?"

Mr Williamson said the alleged victim told a doctor after the incident she did not want to die and argued she said she stabbed herself to protect her daughter.

"We say the lie was told out of love and that Marija's maternal instinct has kicked in."

Defence lawyer Kylie Weston-Scheuber said Ivanisevic's mother, who had a history of bipolar disorder and depression, reported feeling sad and worthless around the time of the stabbing and had inflicted the wound to hurt or kill herself.

"She was in a bad frame of mind on December 6, consistent with evidence that she'd gone downhill after the death of her husband on November 20.

She said the pair's relationship wasn't perfect but Ivanisevic, who looked after her mother and received a carer's benefit, had no murder motive.

It wasn't unusual for Ivanisevic and her sister to tape conversations with their mother to record memories and because of family unrest, she said.

"For you to accept the Crown case you must accept Marija was lying every one of those times she said she stabbed herself and you can't do that."

Dr Weston-Scheuber said it didn't make sense the accused could have flown into a "murderous rage" in the timeframe alleged by the prosecution and her behaviour in going to the service station was "quirky, unusual, but it wasn't a lie".

She also questioned the reliability of evidence from a neighbour who said she heard the accused yell "die" soon before the injured woman was found.

Justice Michael Elkaim will begin his summing to the jury up on Friday.