"In a half hour the house was destroyed, the last band of wind took it down," she said.
The hurricane brought howling wind and heavy rain to the city and knocked out power to more than 700,000 people.
But even at its strongest, Isaac was far weaker than hurricane Katrina, which crippled the city in 2005.
Pauline told of conditions in the midst of the hurricane yesterday.
"There were bands of heavy rain and bad winds coming every 20 to 30 minutes at the height of it," she said.
"There was a small bit of storm damage to the roof at home and bar with lots of downed tree limbs.
"Hopefully when this is over we will have a squeaky clean New Orleans and will finally get rid of Katrina's August 29 funk, because now we have Isaac to remember, and he wasn't as bad as he could've been to New Orleans."
Pauline, who comes from Belfast, has lived in New Orleans since 1990.
She runs Finn McCool's on Bank Street in the city with her husband Stephen.
They re-opened the pub with the help of a generator today.
During Katrina, the couple were forced to leave and then rebuild for six months in 2006.
Finn McCool's was closed yesterday, but reopened today with the help of a generator.
"Where the bar is located is out of power and has been since 7pm on August 28. It was powerless yesterday too," she said.
"Hopefully today we will see the winds down and the electric company can go out and do some repairs. They aren't allowed out until winds drop to 40mph.
"Obviously they'd never be allowed out in Donegal, where 40mph is a summers day."
National Guard troops were still working to evacuate thousands of people's homes west of New Orleans after the storm surge brought on by the hurricane forced water over the banks of Lake Pontchartrain.
Buses were used to move residents out of flooded parts of St John Parish, while authorities worked to rescue others trapped by up to six feet of water.
Isaac's sustained winds dropped to 60mph today, well below the hurricane threshold of 74mph.
New Orleans faced problems such as flooding downed power lines and scattered branches.
But just one person was reported killed in the storm, compared with 1,800 deaths from Katrina.