Julianne Francis Williams, 38, is alleged to have invaded the victim's Kambah home and punched her "seven or eight" times as the victim desperately shielded her stomach in September 2020.

The victim told police Ms Williams, a former girlfriend of the baby's father, carried out the attack the day after she revealed her pregnancy on Facebook.

She claimed she refused demands to "lift your arms up and it'll all be over" as her assailant tried to hit her stomach.

Justice Michael Elkaim said on Thursday there was "no issue that [the victim] was beaten up".

But the ACT Supreme Court has heard Ms Williams denies being the attacker and claims she was not even at the scene.

The 38-year-old has pleaded not guilty to charges of aggravated burglary and assault occasioning actual bodily harm.

Her co-accused, Anthony Daniel McIver, 32, is defending charges of being knowingly concerned in those alleged offences.

His case is that he and Ms Williams were there at the time in question, but that he did not commit a crime.

The pair's judge-alone trial was initially expected to conclude by Friday, but on Thursday the court heard Ms Williams had been admitted to Canberra Hospital and was unable to attend.

With no certainty around when the alleged attacker would be fit for court, prosecutor Elizabeth Wren asked Justice Elkaim to adjourn the trial to a later date.

But Mr McIver's lawyer, Jan de Bruin, proposed his client's case be split from Ms Williams' so the 32-year-old's charges could be resolved without delay.

Justice Elkaim ultimately decided, "with a good deal of reluctance", it would be best to adjourn the matter entirely until September 8.

He listed Ms Williams' case for mention on July 1, "to check on her welfare" ahead of the joint trial's resumption.

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