The Crown and defence both wrapped up their cases yesterday after testimony over 11 days from more than 70 witnesses, including family, friends, workmates, police, professionals and medical experts.
The jury retired to begin its deliberations at 11am today after Justice David Gendall completed his summing up.
After six hours of behind-closed-doors discussions they were sent home at 5pm today, and told to return at 9.30am tomorrow when they will resume their deliberations.
They are deciding whether Milner fatally poisoned her second husband, motivated by money, or whether she has been a victim of an orchestrated campaign of character assassination.
Justice Gendall told the jury to "ignore any comments anyone may have made to you" about the high-profile case.
"You are the sole judges of the facts," he said.
He urged them to go about considering their decision without feelings of prejudice or sympathy for Mr Nisbet or Milner.
"You must be sure your decision is not swayed by emotion."
The jury was reminded that it was up to the Crown to prove Milner's guilt beyond reasonable doubt.
"You may not guess," Justice Gendall said.
The judge issued a question trail to each juror to be used as a guide when coming to their verdicts.
The Crown must prove that Milner had drugged Mr Nisbet with Phenergan without his knowledge and that those drugs caused his death - by either being an operative or substantive cause of death.
For a guilty verdict, the jury must also be sure that Milner had "classic murderous intent" that she meant to kill him.
Justice Gendall also warned jury members that they could not reach a conclusion out of a dislike for Milner.
The defence said Mr Nisbet took his own life.
In final arguments yesterday, the jury heard the case boils down to a choice between scientific and circumstantial evidence.
Crown prosecutor Brent Stanaway said it amounted to an "overwhelming circumstantial case".
Defence counsel Rupert Glover, however, argued it was not a case of murder by poison, but rather an assassination of Milner's character by "poisonous testimony".
Instead of relying on circumstantial evidence, he urged the jury to look at the science.