"I just want to get out of here, it's dangerous," the woman said Sunday, as NATO warplanes bombed the city a day after fighters for the country's new regime engaged in deadly street battles with troops loyal to the ousted dictator.
The street fights continued on the eastern edge of the city, but fighters withdrew on the western side to a bridge just a hundred metres (yards) from the mosque compound. It was there that the US woman and around 150 others sought refuge.
The woman, who gave her name but asked for it not to be published, said the group had left the town of Tawarga -- where she was living with her husband and three children -- back in March to escape NATO bombing.
The residents of Tawarga are accused by the people of nearby Misrata of having played a major role in the months-long siege that city suffered. Misrata held off Gaddafi's forces, but at the cost of 1,400 lives.
As fighters loyal to the National Transitional Council (NTC) advanced towards Sirte in the late summer, those still left in Tawarga fled.
Many Misratans say they will never let their neighbours return, blaming them for a wave of killings and rapes. Tawarga had the distinction of being the only town on the Libyan coast where most of the inhabitants were as dark-skinned as sub-Saharan Africans.
It is now a ghost town, its 25,000 residents dispersed around the country, fearful of revenge attacks by fighters of the NTC, which now controls the whole country except for Sirte and Bani Walid.
In the Imam Malik mosque on the edge of Sirte, the US woman was one of the few fair-skinned people in the group that has been hiding there for a week after spending months inside the city.
The men sleep and socialise in the mosque itself while the women and children live packed into a small one-storey building in the compound.
The American said her father was a Libyan and that she had met her husband while he was working as a labourer in the United States. They decided to move to Libya and settled in his hometown, Tawarga.
When they fled their home they took only a few possessions with them, even leaving their US passports behind them in their haste to escape.
They now have only a slim chance of retrieving them as many of the houses in Tawarga have been looted, and it could be dangerous for them to try and return there.
The woman appeared to know little about what has been happening in Libya since the anti-Gaddafi uprising began in February. She was sceptical when told that the NTC was now in power in the capital Tripoli.
The fighters -- all from Misrata -- manning the frontline nearby bring them food and water, and the ambulances that park under the bridge, waiting to ferry those wounded in battle to field hospitals, give them medical aid.
"The thwar (fighters) treat us well," she said.
She and her husband said they wanted to go and stay with relatives in the south of Libya but did not know how they would get there as they have no transport. Ultimately they plan to reach the United States and wait there until things settle down in Libya before returning one day to Tawarga. "When we have peace and quiet we will come back," she said.