A mother-of-two stole nearly €300 worth of cosmetics from the RDS, a court heard.
Emma Darby (38) was "not in her right mind" when she carried out the theft.
Judge Ann Ryan adjourned the case for the preparation of a probation report.
Darby, of Marshfield Avenue, Clongriffin, pleaded guilty to theft.
Dublin District Court heard a garda was on plainclothes patrol at the RDS Simmonscourt at 3.30pm last March 14.
He saw Darby place the cosmetics into a bag and pass all points of payment.
The officer stopped her outside and told her what he had observed.
The goods were worth €292 and Darby was arrested and taken to Donnybrook Garda Station.
She "wasn't in her right mind" when she stole the goods, her lawyer said.
The property was returned to the owner and was in a resaleable condition, the court heard.
Darby had 37 previous convictions, most of which were for road traffic off- ences.
She had flagged her guilty plea before the planned hearing.