Mary Hand (34) was found "flashing her private parts" to security workers at a city centre Supermac's and called one of the investigating gardai a "dyke", when she was confronted over her behaviour.
Hand was grieving the recent death of a brother and had gone out and drunk so much alcohol on the night she had no recollection of the incident.
She was convicted of a public order offence and fined €300 when she appeared in Dublin District Court.
Hand, of Church Road, Mulhuddart, pleaded guilty to a charge of failing to obey garda directions at Supermac's, O'Connell Street, on May 3.
Garda Thomas Stacey said in evidence he was on duty at 1.10am on the night in question when he was flagged down by security staff from the restaurant. The staff member told him a woman was causing a disturbance inside the premises.
"I entered the premises and observed the defendant flashing her private parts at security staff in Supermac's," Garda Stacey said.
"She was shouting abuse at them, calling them p***ks and saying she was going to box the heads off them."
The garda approached her and directed her to stop what she was doing. Hand "point blank refused to desist" and turned her verbal abuse on the gardai.
The court heard Hand had been given the benefit of the Probation Act in January for threatening, abusive and insulting behaviour and failing to obey gardai.
She also had a previous conviction for drunk driving, dating back to July 2002.