Kathy Lin stood by her accused husband Xie

Her husband was accused of murdering five members of her beloved family.

And for more than six years Kathy Lin has been convinced of his innocence.

When she took the stand at Robert Xie's third trial in May Kathy said the pair had gone to bed at around 2am in the morning of July 18, 2009, after having dinner with her parents, her brother Min Lin and her two nephews, Henry, 12, and Terry, nine.

Her husband did not leave the house afterward, she testified.

Kathy repeatedly broke down as she described how the pair had gone to her brother's home in the morning after receiving a phone call to say he hadn't turned up to his Epping newsagency in Sydney's north west.

"I remember blood ... I saw the blood on wall. I saw next to my sister-in-law, I saw body under doona," she cried.

Xie had never shown any resentment towards her father and mother, Yang Fei Lin and Feng Qin Zhu, and loved her nephews as though they were his own, Kathy maintained.

"If my parents asked him to do something, my husband was always happy to do it," she said.

Kathy denied she was deliberately lying in court to protect her husband, and said they had been fearful of NSW police, believing they would "plant evidence against us" and use her husband as a "scapegoat".

"I know in my heart my husband love me and my extended family," she told the trial in July.

The crown said she was an unreliable witness who was trying to protect her husband, giving contradictory versions of events.

But on Tuesday, after hearing nine months of evidence, the jury deliberating in Xie's trial was discharged because it couldn't reach a verdict.