"We can't go to the upper floor because it might fall on us," she said.
She is among thousands of angry Lebanese reeling from a blast that killed at least 145 people, injured 5,000 others and left up to 250,000 without habitable homes.
Officials said the figure was likely to rise.
At the port, destroyed by Tuesday's giant mushroom cloud and fireball, families sought news of the missing, amid mounting anger at the authorities for allowing huge quantities of highly explosive ammonium nitrate, used in making fertilisers and bombs, to be stored there for years in unsafe conditions.
There was a small but violent protest near an entrance to parliament in central Beirut, where riot police deployed after some demonstrators burned objects and hurled rocks at security forces, footage from local broadcasters showed.
The government has ordered some port officials be put under house arrest. State news agency NNA said 16 people were taken into custody.
A judicial source and local media said Beirut Port General Manager Hassan Koraytem was among them.
The central bank said it had decided to freeze the accounts of Koraytem and the head of Lebanese customs along with five others.