She appeared before Belmullet District Court charged with assaulting a member of the Garda Síochána on Mc Grath's Pier in Poll a Tómáis in north Co Mayo on 11 June 2007.
She was found guilty and ordered to pay a fine of €1,000 and another €1,000 to the garda benevolent fund.
Harrington was also found guilty of another public order offence on a separate date and ordered to keep the peace for 12 months.
Harrington refused to sign the bond and was therefore found to be in contempt of court.
Judge Mary Devins jailed her for 28 days for the garda assault, and a further two days for being in contempt of court, to run concurrently.
Judge Devins also recommended that Ms Harrington should get a psychiatric assessment.
