When officers arrived at the house the woman, Victoria Heyburn, was sitting in a car and refused to provide them with a sample of her breath.
Heyburn, of Carlton Cottages, Belleek, appeared at Fermanagh Court and denied being in charge of the vehicle with excess alcohol and failing to provide the specimen.
The case was to have been contested but when the prosecutor withdrew the first charge and she pleaded guilty to the second, of failing to provide a specimen of breath.
She was fined £250 and given 10 penalty points after the court heard she had a previous conviction for a similar offence for which she been banned from driving for 12 months.
Defence solicitor Michelle McVeigh said Heyburn had returned from England to care for her elderly mother, who has since passed away. On the day in question she had bought a bottle of alcohol in Garrison. When she returned to the house at Barr of Slattinagh her brother refused to let her in and she remained in the vehicle. It was her brother who contacted the police. When they arrived Heyburn believed she was entitled to refuse to provide them with a sample of her breath as she was on private property.
District Judge Liam McNally said there appeared to be a real issue in the case "that she drove the car up to where it was stopped, but that charge has been withdrawn".
He told Heyburn the prosecution had withdrawn the main charge, that she was in charge of the vehicle with excess alcohol, and he accepted that she was on private property.
He said there seemed to be an argument that she was driving.
"The only reason she is not being disqualified is that she was on private property," stated the District Judge.