Twenty-year-old Aine Hill from Dunclug Park, Ballymena, was also ordered to pay a £15 offender levy.
Prosecuting counsel told the court on April 28 last year at approximately 2.40pm, police attended the Sandymount area of Magherafelt to deal with an incident of disorderly behaviour involving another person.
She said while police were attending to this “rowdy individual” at a house in which there were five people they spoke to the defendant in relation to breaching health regulations.
The lawyer explained that those present in the house came from four separate households which was a breach of the Covid regulations.
The defendant was interviewed by the police and described being at “a party house”, counsel added.
A defence solicitor said that a fixed penalty notice had been issued but it could not be served on the defendant as she could not be located.
She said Hill at the time had moved address a number of times and was not able to avail of the penalty.
Pleading for leniency, the lawyer described the defendant as a “vulnerable young woman.”
Deputy District Judge Noel Dunlop said that he would keep the fine to £150.
Mr Dunlop refused an application for legal aid.