As you said, there are still several hundred more children separated from their parents and no answer on when they will be reunited. Gio Benitez is still in El Paso. You learned that little girl we heard crying for her aunt, we've heard more about her. Reporter: Yeah, that's right. She and her mother are now hoping to be reunited very soon but, you know, we're also learning that so many of these children aren't even by the border anymore. They've been sent to shelters all across the country and some have been reunited. This morning, some of those children reunited with their families. Telling the associate press around 500 children have been reunited. Unclear how many are still being retained with relatives and whether trump's executive order had any impact. That clear voice captured in that recording of children's cries. Mommy. Reporter: That audio first obtained by propublica. She was heard begging a supervisor to call her aunt after she and her mom were separated. She has the number memorized. "Titanic". Reporter: On Wednesday propublica was there. Reporter: She told her aunt and cousin she wants to take a hot bath when she's out of the detention center. It's been a week since they crossed the border. Propublica reporting she's now in a facility in Phoenix 1200 miles from her mother who it says is being kept in port Isabelle, Texas. Reporter: The fact that she was able to memorize this phone number turned out to be a really lucky thing for her. Many of the kids who come to this country who are her age or below, you know, don't know things like phone numbers. Reporter: Her aunt was filmed in silhouette because she's afraid her speaking to the press will affect her and her daughter's asylum case. Her aunt says during their first phone call the little girl was crying, screaming and begging. Propublica reporting they told her mother they'd be reunited soon. She's one of the few who could track down her family on her own but for so many of them that road to the reunion is just so unclear. As we heard, many of these children are too young to speak or much less memorize a phone number, so what happens with them? Reporter: You know, advocates are worried about this because they fear that if this paperwork is just not complete, in they fear it's unclear that really they won't be able to find -- they hope they'll find their family but fear they won't be able to ever. So heartbreaking. Scary thought right there. Thank you.