Tonight you're about to hear the story of one little girl who was lucky enough to remember a family member's phone number. What about those two young to remember or know? On the border our team with the border patrol saying they're just trying to do their jobs as they're told. ABC's Marcus Moore. Reporter: Overnight a tearful reunion in Maryland between a mother from Guatemala and her 7-year-old son. Reporter: Just one of the some 500 children the government says has been reunited with their parents since may, but more than 1,800 children are still waiting. Many of them very young with know way of finding their parents on their on. Among them 6-year-old Alison Jimena Valencia Madrid from El Salvador whose desperate cries were recorded, then obtained by propublica. Reporter: The little girl who begged a supervisor to call her aunt after being separated from her mother. Reporter: And tonight we hear her talking to that aunt from a detention center by phone. Propublica listening in. Reporter: Advocates say it was key she had memorized her aunt's number. The fact she was able to recognize the phone number turned out to be a really lucky thing for her. Many the kids her age and below don't know the phone number. Reporter: Tonight Alison's aunt tell us she has finally talked to her mom. But there is no word on when they will be reunited. Tonight the government is giving few details on how it will reunite nearly 2,000 families scattered around the country. Every day more people cross the border. We have saw the operation firsthand with a ride along. Earlier in E day agents were raiding an alleged stash house. We're doing -- everything we do is for the United States. We're here to protect the people of our country. Marcus Moore join us tonight from Texas where Borr patrol just released young mothers from custody. David that's right. We saw a bus load of young mothers with children in their arms. One woman told me she was afraid her son was going to be taken away. David. Marcus Moore, thank you. There are severe storms we're