Last year, the veteran Coronation Street star arrived at a police station near her home after her daughter - Maxine Ashcroft - was arrested on suspicion of driving under the influence of alcohol.
Officers advised Barbara Knox - who was slurring her words - not to drive home herself, as she had also been drinking, and offered her a lift home.
She declined the offer and ignored their advice - and was, subsequently, pulled over for drink-driving.
Following her subsequent arrest, a blood test showed she had 85mg of alcohol in 100ml of blood. The legal limit is 80mg.
Last April, Barbara denied the charges made against her.
But this morning she changed her plea to guilty at Crewe magistrates court.
The judge overseeing the case said that it was 'regretful' Barbara had taken so long to plead guilty, as, in the process, she wasted a great deal of the court's time and money.
She has been fined £3,000 and banned from the road for 12 months after admitting drink driving.
The actress must also pay prosecution costs of £1,750.
Barbara Knox made no comment as she left the court, although one member of the public did ask (clearly confusing her with her on-screen persona) "you alright, Rita love?"
However the Corrie star's lawyer, Nick Freeman, did speak out, and accepted the actress was "the author of her own misfortune".
He said his client "considers drink-driving to be serious" and had not sought to justify her actions.
From Coronation Street's Rosie Webster to Page 3 girl: Helen Flanagan's life in pictures
1 of 15Click through for soaps, selfies and scandal..
She hit our screens as Corrie's innocent young Rosie Webster in 2000, and was soon thrust into a world of footballers, selfie-hiccups and Page 3 appearances..
2 of 15D.O.B
Born 7 August 1990 in Lancashire (23 years old).
3 of 15Family
Parents: Julia and Paul
Sisters: Jane, 32 and Jessica, 22 (pictured)
4 of 15Helen flanagan 2000
Helen first hit fame as 10-year-old Rosie Webster in Coronation Street in 2000. In 2006 she was nominated for 'Best Dramatic Performance' and in 2007 for 'Villain Of The Year'. She left the soap in 2011.
5 of 15I'm a Celebrity...Get Me Out of Here!
Helen appeared on the reality show in 2012. She was continually nominated for gruelling tasks, and despite being squeamish at first, her efforts soon impressed. She finished in seventh place out of the twelve celebrities who appeared.
6 of 15Sexiest Women poll
In 2012 Helen was voted the most attractive British candidate in the 2013 FHM 100 Sexiest Women in the World poll.
7 of 15THAT selfie
Helen caused a Twitter storm when she posted up a gun selfie hours after the Sandy Hook Massacre. She made a public apology on Daybreak, describing it as the 'most stupid thing she had ever done'.
8 of 15Page 3
In September 2013 Helen posed topless as a Page 3 girl.
9 of 15PETA
Helen posed naked for an animal rights campaign PETA in 2013.
10 of 15Relationship
Helen lives with her long term footballer boyfriend Scott Sinclair.
11 of 15Hair
She is not afraid of trying new styles.
12 of 15Burglary
She came face to face with three armed burglars in 2013, after tweeting “Super tired today, which makes me emotional, sensitive and mental! Can’t wait to have my boyfriend home.”
13 of 15Playboy
She is keen to pose for Playboy, explaining: “I’d love to do Playboy. I mean, Marilyn Monroe did Playboy and she’s my idol. I’ve always enjoyed modelling – you can play with it and have fun and all my work is tasteful.”
14 of 15Blonde moments
Helen once mistook a reflection for a murderer and had a hotel evacuated. She later explained: “I tend to do things like that”. Tell that to the 500 guests quivering at the emergency meeting point.
15 of 15Holby City
Helen will make a guest appearance on Holby city in summer 2014, adding: "I'm really pleased to be working with the BBC in a show that I really enjoy."
Holby City's executive producer Oliver Kent added: "We are all hugely excited to have Helen on the show - she is a superstar soap actress and she is going to ruffle some feathers with Colette! It is definitely an episode to watch."