In an unsent letter months before her death, author Colleen McCullough said she would have to "take further steps" if she couldn't trust her husband to stop stealing from her, a court has heard.
"You subject me to a lot of pressure and criticism simply to fuel your desire for more money," Dr McCullough allegedly said in the October 2014 letter.
"If I cannot trust you not to steal from me - for that is what it is - then I will have to take further steps."
Barrister Kim Morrissey on Thursday said the letter offered a snapshot of Dr McCullough's thinking towards her husband, Ric Robinson, at the time he claims the author was changing her will to leave him everything.
"This is Dr McCullough speaking from the grave," Mr Morrissey told the NSW Supreme Court.
The barrister is acting for Dr McCullough's friend and executor, Selwa Anthony, who claims the University of Oklahoma Foundation is the sole beneficiary of her estate as per a July 2014 will.
Mr Robinson, however, says the Thorn Birds author later left him everything.
During his closing address, Mr Morrissey said Dr McCullough's letter showed antipathy towards her husband and was inconsistent with her wanting to leave him everything.
The hearing continues.