Kareena Gilmore, of Cronk Grianagh Estate, admitted an offence of disorderly behaviour on licensed premises.
The incident was said to be part of a long-running feud which had lasted 12 years.
The court heard that, while in the pub, Gilmore grabbed the complainant by the coat and attempted to headbutt her.
The two women were said to have had a hostile relationship and Gilmore was removed from the premises before being arrested.
When interviewed by police, Gilmore told them that the complainant and her had a long history and claimed that the woman insulted her every time she saw her. Gilmore said the woman had made an inflammatory remark which had sparked the incident.
Gilmore also claimed that she was terrified of the woman so she would not have done anything to provoke her.
The court heard that she has no previous convictions.
Defence advocate Emily Johnson said: ’This is the result of a substantial history with the individual.’
Ms Gilmore said it was the culmination of 12 years of difficulties.
’She has no history of doing this previously,’ she said. ’It was very much out of character.’
Magistrates also ordered Gilmore to pay £50 prosecution costs which she will pay, along with the fine, at a rate of £100 per month.