The former fiance of billionaire James Packer now lives on $100 a week.

Tziporah Malkah appeared in court on Friday to plead guilty after a night of erratic driving in Melbourne when she reversed into a parked car.

Malkah, 44, the model formerly named Kate Fischer, was seen hitting three roundabouts in Toorak about 5.35pm on January 3.

One person followed her and called triple zero before Malkah reversed into a parked car, Melbourne Magistrates Court heard.