Over the past four months, news from the border has chronicled the stories of families detained and separated — many of them seeking asylum from gang violence in Central America. Children as young as 8 months have been taken from their parents and sent across the country to children’s shelters, privately run detention centers, and, some, to foster families. Now, 20 days after a court-imposed deadline, more than 550 children still have not been returned to their parents, at least 300 of whom have been deported.