Amy Foster's VW Touran was stopped on Cheapside, at 7.40pm, on May 24.
A test revealed she had 44 mcgs of alcohol in 100 mls of breath, when the legal limit is 35 mcgs.
Foster, who had no previous convictions, said: "I just apologise for taking up your time. I didn't realise I was over the limit.
"I had just come back from holiday and the alcohol was still in my system."
Foster, 34, of Kilton Road, admitted drink driving when she appeared at Mansfield Magistrates Court, on Thursday.
She was fined £253, with £85 costs and a £30 government surcharge.
She was banned for 12 months, but she was offered a drink-driver's rehabilitation course which will reduce the disqualification by 91 days if completed by February 1, 2020.
Here are the latest cases heard at Mansfield Magistrates Court.