"They were very scared and are still very scared", she adds, but she says her siblings immediately recalled the 8.1 quake that hit Mexico City in 1985.
The toll has continued to rise steadily since Tuesday's 7.1 magnitude quake, the second to strike the central American country in 11 days. As of midnight Wednesday, 30 people who either worked at or attended the school were still missing.
However, as of Thursday afternoon, authorities had determined the whereabouts of all the school's students, both alive and dead, Sarmiento said. But there are indications that someone may still be alive in the rubble, he added.
Yesterday's 7.1 quake struck on the 32nd anniversary of the 1985 natural disaster that killed more than 5,000 people. "God bless the people of Mexico City". Schools have closed indefinitely, and millions remain without power.
Three survivors were found about midnight as volunteer rescue teams known as "moles" crawled deep under the rubble.
Army soldiers and navy personnel, who are leading the search effort, said most of those rescued had been taken to a civilian hospital.
A powerful quake turned buildings in Mexico to rubble, destroying facilities and starting fires in major cities in the country's capital, as well as neighboring cities close to the epicenter. Mexico's national coordinator for civil protections Luis Felipe Puente tweeted late on Wednesday that the death toll stood at 230. The highest number of fatalities, that of 137, was in Mexico City.
The Education Ministry said 209 schools have been closed, 15 of them with severe damage.
Meanwhile, power has been restored for the almost 4 million people who lost it during the natural disaster.
El universal newspaper reported one of the girls trapped, Fatima, had messaged: "I'm fine, I'm with four other trapped children, help us, we're thirsty".