She was remanded at large, with sentencing postponed until the completion of her rehab treatment. A monitoring date was set for next month.
A photograph application made by media was declined by the community magistrate, on the grounds it would cause undue harm to her two children, aged 6 and 8.
Antunovich was tested about 6.30pm on December 30 after a concerned motorist followed her to a property on Barrett Rd, Riverhead and called police.
The motorist told officers there were two young children in the car.
Antunovich's alleged breath-alcohol level was 1568 micrograms per litre of breath. The legal limit is 400mcg.
A source has told the New Zealand Herald that Antunovich said at the time she had consumed half a litre of vodka shortly before driving.
Waitemata road policing manager Inspector Mark Fergus has said Antunovich was "seen to be swerving into other lanes and driving off the shoulder of the road".