AURORA — Before this, she had never been away from her daughter for more than a week.

Aurora Yadira Mireles Terrazas has spent the past two months struggling to stomach meals or get any real sleep in the detention dormitory where she’s been locked up with around 20 other women, also separated from their families and loved ones.

Talking into a phone wired through a glass panel at the U.S. Immigration and Customs Enforcement detention center in Aurora, Terrazas’ eyes well over with tears every...