Her children cry over the phone begging that she find someone, anyone, to take them out of a government-run shelter in New York.
The mother's throat ties into a knot, as she holds back tears.
She's nearly 2,000 miles away, living under a tarp with her 8-year-old daughter in a public park in Reynosa, Mexico, a cartel-ridden and kidnapping hotbed.
"Find someone to help us," her sons, ages 10 and 15, say over the phone.
She keeps listening and doesn't have the heart to tell them, again, that none of their relatives in America are willing to take them out of the shelter.
"I feel incomplete," she told CNN. "I want to do something [for them] and I can't."
This 34-year-old Guatemalan mother shared her story with CNN over the phone and asked not to be identified out of fear for her safety.
Her story reveals what are, perhaps, the unforeseen consequences of a kind of family separation immigration advocates say was created by US government policies that allows children crossing the border alone to reunite with family in America. At the same time, under the Trump-era pandemic public health rule known as Title 42, adults and children traveling with a parent are swiftly returned to Mexico.
While President Joe Biden pledged to undo his predecessor's hardline immigration policies, Title 42 is still used by border authorities today and highlights Biden's struggle in dealing with the historic surge of migrants at the southern border. Republicans claim Biden swung open the southern border and is failing to secure the Rio Grande. All while immigration advocates are putting pressure on Biden, saying his immigration policies aren't doing enough to protect the rights of asylum seekers, and vulnerable migrant women and children.
Exactly how many children have crossed the border alone, leaving their families or parents behind in Mexico, is unknown. But earlier this year, the number of unaccompanied migrant children surged, with immigration authorities encountering nearly 14,000 minors in April and nearly 16,000 in March, according to US Customs and Border Protection.
In April, a top Border Patrol official told CNN that more than 400 children who were taken into US custody without their parents in the Rio Grande Valley had first tried crossing with their families. The desperate situations that prompted all these families to make the impossible choice to separate, perhaps will never be known.
But the painful consequences of those decisions are beginning to reveal themselves on both sides of the border.
CNN has learned some parents whose children crossed the border alone are in Mexico; their children are in US government custody; and the family members who pledged to be their guardians in America have backed out, or don't meet the criteria to take children out of government custody.
Immigration attorney Natalia Trotter says she represents at least three families in those circumstances. She works for RAICES, a non-profit organization that provides pro-bono legal services to low-income immigrants.
"I have, on several occasions, had to explain to minors that they do not have viable sponsors in the US," Trotter said. "The look on their little faces when they realize that no one can receive them is utterly heartbreaking. These children express confusion, fear, sadness and deep pain."
The US Department of Health and Human Services did not return CNN's request for comment.
Family backed out of sponsoring her sons
From the park in Reynosa, the mother cries over the phone as she explains to CNN how she crossed with her children on April 22 and was returned to Mexico by US immigration authorities the next day.
Three days later, she says her sons, ages 10 and 15, crossed the border alone. How and why they traveled without her still haunts her, because she says she doesn't exactly know. She denies sending them across by themselves.
"It's been a total nightmare," she said.
They were in Reynosa, and one moment her sons were with her, she says, and the next they were gone.
For the Guatemalan mother what followed were days of agony, not knowing anything about her sons until a social worker called her saying the boys were in a shelter in San Antonio, Texas.
At that point, she breathed a sigh of relief, since family in the US had pledged to take her and her children into their home.
But the joy didn't last long.
She says the committed "sponsors" backed out once they learned the US government required they submit fingerprints and agree to a home visit.
Desperate pleas from her children
The Guatemalan mother switched a phone call to a video call to show her surroundings. Birds could be heard chirping around her.
The phone screen revealed the urban public park in Reynosa had dramatically changed since mid-April.
Most of the green spaces are now covered with multi-colored tents; and grey tarps fan from the gazebo that's at the center of the property. All signs more migrants have arrived in the past month, and so has the rainy season.
The mother estimates the tent city is home to hundreds of migrants on any given day and says she's not the only parent there with children in US government custody.
She says two women, one with a 15-year-old daughter and another with two sons, ages 10 and 17 -- are in the same agonizing situation she is in. Their children crossed the border alone and now have been in government shelters for about a month.
The mother breaks down crying as she recalls the poverty and violence they left in their home country, and her children's desperate pleas never to go back.
"Do everything possible to find someone to sponsor us," she says her children tell her by phone. "I don't want to return to Guatemala."
'It's the only way to get across'
In April, CNN talked to a Salvadoran mother in Reynosa who struggled to talk about the moment she watched her sons crying and holding hands as they crossed the border alone.
"I felt like I was dying," she told CNN. "I didn't want to separate from them."
Her sons, ages 12 and 16, didn't want to separate either. But after crossing into the United States twice and getting kicked out, they felt that splitting up was the only option for their family.
"It's the only way to get across," she says her oldest son told her.
And with a wave, the boys were gone. And she was left on the Mexican side of the Rio Grande wondering if they had made a terrible mistake.
As she tells CNN her story from a shelter for deported migrants she holds her 7-year-old son with special needs and wipes away tears streaming down her face.
"It was the only choice... so they could have a better future," she said.
This mom didn't want to be identified out of fear for her family's safety. Her story highlights the impossible choices some migrant parents say they are left with when US immigration authorities automatically return them to dangerous Mexican border towns.
Humanitarian exemption helps mom with her children
Immigration attorney Natalia Trotter says, "although most unaccompanied minors are eventually reunified with family members in the United States, minors whose parents are stuck in Mexico often do not have reunification options."
"The frustrating and discouraging part about this situation is that these children do have viable sponsors, sponsors from whom they should have never been forced to separate," Trotter said.
But in one case last week, Trotter says, her client, a mother who was in Mexico, was granted entrance into the US to reunify with her children -- who had been in a government-run shelter. In these types of cases, both the mother and the child are given notices to appear before a judge to continue their immigration cases.
That type of legal relief, Trotter explains, is not guaranteed. It's a humanitarian exemption to Title 42, for migrants in certain vulnerable situations or with other compelling reasons, such as separation from their children.
Advocates call for an end to Title 42
Title 42 is a Covid-19 public health policy that was put in place by the Trump administration in early 2020 that allows immigration authorities to swiftly return migrant families to Mexico.
Biden continued the policy when he took office. In April, Customs and Border Protection expelled more than 111,000 people under Title 42, the agency said.
Trotter and other immigrant advocates are calling for the end of Title 42. They argue that US law allows asylum seekers to enter the US and have their cases heard. And that the Trump-era policy, which swiftly returns families to dangerous Mexican border towns, is "forcing" some parents to send their children across the border alone.
"Parents are faced with the decision to either remain together as a unit and face the possibility of assault, rape, kidnapping and death or send their children across to an unknown that at least presents the prospect of physical safety for the minors," Trotter said.
During a congressional hearing last week, Homeland Security Secretary Alejandro Mayorkas declined to provide a timeline for when the pandemic-related border policy will be lifted.
"We are watching the data, we are watching the science led by the CDC, and we will no longer rely upon Title 42 when there is no longer a public health imperative basis to do so," Mayorkas testified.
"Tragically, this forced separation is the result of a failed immigration policy implemented by the prior administration and not extinguished by the current one," Trotter said.
'I have to have faith'
From the public park in Reynosa, the mom remembers the times when she could embrace all her children but was surrounded by poverty and violence, and then her sons' phone plea reverberates in her mind.
"Find someone to help us," she says her sons tell her by phone. "Mommy, I don't want to return to Guatemala."
The mom has trouble putting her pain, despair and hopelessness to words as she cries over the phone and clutches to the one thing that is certain in her life, her faith.
She goes on to say, she has no money, no home. Her 8-year-old daughter, who only has two sets of clothes to her name, is covered in mosquito bites. And she doesn't know when or how she will embrace her two boys again.
"Every day is a nightmare," the mom said. "But I have to have faith."