Inga Hickman, 31, from Worcester, was also given a £385 fine by Worcester Magistrates Court.
The mum of two small children, who is now three months pregnant with her third baby, crashed her Audi A4 into a Ford Focus, which she shunted into a third car on July 4 2012.
Police officers were told by three witnesses that a female driver had left the scene following the crash.
Hickman - who matched the description given by witnesses - was then seen approaching the car in what was described as a 'wet and bedraggled state'. She was unsteady on her feet, and provided a breath test which showed 73mcg of alcohol in 100ml of breath. The legal limit is 35mcg.
However after being taken to the local police station, she refused a second breath test and failed to provide officers with her details.
Hickman pleaded guilty to failing to provide a breath test, and was ordered to pay £150 costs and a £15 victim subcharge, along with her fine of £385. She was also banned from driving for nine months.
Mark Lister, defending, said: "She has a seven-month-old daughter and the incident happened three months ago when the child was very young. She had been under a lot of stress and anxiety following the birth of her child."
Magistrate Heather Osborne said: "We have taken into account your guilty plea and what has been said about your state of mind. However, this is a very serious matter and we have no option but to disqualify you from driving."
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