A crying Michelle Bridges has apologised outside a Sydney court for her “gross error in judgment” after the TV personality and personal trainer was caught drink-driving with a child in the back seat.

The 49-year-old fitness guru blew 0.089 after she was stopped for a random breath test on New South Head Road in Bellevue Hill on Australia Day.

Magistrate Allison Hawkins convicted Bridges on Tuesday, handing her a $750 fine– although the magistrate accepted the incident had been “humiliating” for the former reality TV star.

Bridges’ licence was disqualified for three months and she’ll have to drive with an alcohol interlock for one year from April 26.

“I would like to apologise to my family, my friends and my community for this gross error in judgment,” Bridges said outside Waverley Local Court.

“The consequences of these actions will haunt me forever.

“I ask for your forgiveness and I thank you for your support.”

Agreed facts state Bridges hit her brakes suddenly and changed lanes when approaching the random breath test about 11.30am on January 26.

Bridges told police she had used mouthwash five minutes earlier and that she had drunk alcohol the previous night.

“Police noted [she] appeared nervous, her hands were shaking and her voice was trembling,” police facts say.

After giving a positive alcohol reading roadside, Bridges told police she’d drunk a glass of wine and four vodka sodas from 8pm the previous day.

Bridges, who was a personal trainer on TV show The Biggest Loser until 2015, has also authored books and magazine columns and has an activewear line.

She has a five-year-old son, Axel, with her former partner, fellow Biggest Loser trainer Steve Willis, and runs an online weight-loss program.

-AAP