[Watch an episode of “The Weekly” about the youngest child separated from his parents at the U.S.-Mexico border.]

At the time, Ms. Acevedo worked for Bethany Christian Services, a foster care and adoption agency that has a federal contract to house immigrant children. She took the job out of college, hoping to help people with whom she could identify — having come to the United States, albeit with her parents, when she was 2.

Ms. Acevedo was just settling into the role when things suddenly became more chaotic, in the late summer of 2017. Unlike the teenagers she was used to working with, who had intentionally crossed the border alone, the separated children who began to arrive were inconsolable when they reached her. Each new one seemed to traumatize the rest all over again. “It was horrible,” she said. “We could not do work. It was just a classroom full of crying kids all day.”

Even after covering family separations for over a year, as an immigration reporter for the National desk at The New York Times, I was struck by how much they uprooted not only the lives of family members who were divided from each other, but also the people like Ms. Acevedo who were charged with caring for them. While she was on call, Ms. Acevedo had to be available 24-7. She often waited up after midnight to meet newly separated children arriving at her office, transported from the border by contract workers. She would be roused from bed by phone calls about children who refused to eat or leave their rooms until they were allowed to speak to the parents from whom they had been separated.

Ms. Acevedo was particularly good at soothing them during outbursts, which usually meant going from classroom to classroom and pulling up videos of songs from “Frozen” or “Moana” on her phone. It helped that she could identify with the children. She still remembers the day in first grade when she had to participate in a classroom discussion about family. She didn’t know how to say in English that she didn’t have any siblings, so she lied and said she had a brother.