Stacey Clarke, 19, pleaded guilty to two charges of unlawful assault and one charge of using abusive language in a public place.

Police prosecutor Senior Constable Ivan Blomeley told the court Clarke, an Allendale resident, had been drinking at the hotel in March. At about 8pm she had started to get aggressive.

A bartender told her she was banned from the hotel for three months.

Clarke lunged at the bartender from across the bar and another person pulled her off the bar, he said.

He told the court a female patron of the hotel confronted Clarke.

The accused then ran the length of the bar into the bistro where the 56-year-old patron was and pushed her backwards over a chair. The woman suffered bruising and swelling to her arm and leg, Senior Constable Blomeley said.

Defence lawyer Mike Wardell said his client's life had improved after a problematic childhood and she had been in full-time employment for the past six months.

"She wants this matter resolved today so she doesn't have to take any more time off work, which shows some responsibility," Mr Wardell said.

Magistrate Michelle Hodgson told Clarke these were serious charges.

"The barmaid was just doing her job and the lady in the bistro didn't need that sort of harassment," she said.

She placed Clarke on a 12-month good behaviour bond and ordered her to do an anger management and positive lifestyle course.