The 27-year-old mother and her son crossed the border into Texas in May seeking asylum from Brazil. Lidia was arrested, charged and detained, and Diogo shipped to a government shelter in Chicago.
"We were told by an ICE agent we were going to see each other within two days," Lidia said.
But that didn't happen.
For weeks, attorneys said, Diogo sat in a cell alone, quarantined with chicken pox and with no idea when he'd ever see his mother again. That's how he spent his 9th birthday.
A federal judge in Chicago on Thursday ordered Diogo's immediate release from detention.
After her son was taken, she had no idea where he was until another detained mother said her child knew a boy named Diogo in a Chicago shelter. She has been told the soonest he could be released would be in late July.
"I cried almost every day when I wasn't with my mother," said Diogo through a translator.
Thursday, a federal judge in Chicago demanded Lidia and Diogo be legally reunited.
"We think this may open the door so that this is the end of this crisis," said their attorney Jesse Bless.
Judge Manish Shah said Lidia Karine Souza can have custody of her son, Diogo, who has spent four weeks at a government-contracted shelter in Chicago. The mother, who has applied for asylum, was released from an immigrant detention facility in Texas June 9.
Lidia and Diogo are heading to Boston to begin their new American life with the safety of asylum.
The decision came two days after a different judge ordered the government to reunite more than 2,000 immigrant children with their families within 30 days, or 14 days for those younger than 5. Souza's attorneys nonetheless moved forward with an emergency hearing in their lawsuit against the Trump administration to demand her son be immediately released. He has spent four weeks at a government-contracted shelter in Chicago, much of it alone in a room, quarantined with chickenpox. He spent his ninth birthday on Monday without his mom.
When Lidia Souza would call her 9-year-old son - allowed just 20 minutes per week - he would beg his mom though tears to do everything in her power to get him out of U.S. government custody and back to her.
She searched for weeks to find Diogo after the two were separated at the border. When she was released, she filled out nearly 40 pages of documents that U.S. officials told her were required to regain custody.
Then they told her that the rules had changed and that she needed any family members living with her in the United States to be fingerprinted and still more documents. This was not the safety she had sought for herself and her son. This was not the American dream.
"This ... is a nightmare," she said, sitting in a suburban Chicago hotel, still waiting to be reunited with Diogo, from whom she'd never spent more than a week apart before this.
Attorneys pleaded their case in front of a federal judge at the Dirksen Federal Building in the Loop Thursday morning.
Souza said, through an interpreter, the process has been agonizing - the wait, "heartbreaking." She has been separated from her son since late May and has been doing everything in her power to get him back.
"I am very nervous. I'm faithful and I really believe that today I will have my victory," Souza said through an interpreter, Juana Mazon.
The 27-year-old, who was seeking asylum in the United States, headed to federal court Thursday for an emergency hearing.
Her attorneys filed a lawsuit against the Trump administration on Tuesday to demand her son, 9-year-old Diogo, be immediately released, despite a federal judge's order to reunite more than 2,000 children with their families within 30 days, or 14 days if the child is younger than 5 years old.
Souza and her attorney said Diogo has spent four weeks in a government-contracted shelter in Chicago, quarantined with chickenpox and alone.
The government argued that Diogo was an unaccompanied minor, but Souza's attorney, Britt Miller, disagreed.
"The basic argument we made was simply that we don't believe, under the relevant statutes and regulations, that Diogo is an unaccompanied minor. To the extent he was rendered unaccompanied, he was rendered unaccompanied by the government when they took him away from his mother," Miller said. "The status of a child is assessed when you come into the country. He was not unaccompanied when he came into the country. He was accompanied by his mother."
At Thursday's hearing, Shah questioned Department of Justice attorney Sarah Fabian about whether the government has a process by which the boy's status could be switched from "unaccompanied" to "accompanied minor," making it easier to release him promptly to his mom. He was automatically designated "unaccompanied" after his mom was initially detained at the border.
"Not to my knowledge, your honor," Fabian answered.
After a pause, Shah said the lack of a process could raise major constitutional issues. He didn't elaborate.
For days and weeks now, some of the hundreds of parents separated from their children at the Mexican border by the Trump administration have been battling one of the world's most complex immigration systems to find their youngsters and get them back.
For many, it has been a lopsided battle, and a frustrating and heartbreaking one. Most do not speak English. Many know nothing about their children's whereabouts. And some say their calls to the government's 1-800 information hotline have gone unanswered.
Huge logistical challenges remain, and whether the U.S. government can manage to clear away the red tape, confusion and seeming lack of coordination and make the deadline remains to be seen.
Among the complicating factors: Children have been sent to shelters all over the United States, thousands of miles from the border. And perhaps hundreds of parents have already been deported from the U.S. without their children.
Jesse Bless, an attorney from Jeff Goldman Immigration in Boston, one of two firms representing Souza, said some parents who are trying to get their children placed with friends or relatives in the U.S. are being asked by the government to provide, along with fingerprints of relatives, utility bills and lease information, which many newly arrived immigrants don't have.
Souza and her son were separated after she requested asylum, arguing her life was in danger in her native Brazil. "I came out of necessity," she said in an interview with The Associated Press on Wednesday.
She was released from a facility in Texas on June 9. Her attorneys argued in court that she has secured housing with family and friends in Massachusetts, where she can stay with her son, and that the proper background checks have been done.
Souza was able to spend one hour with Diogo at a separate facility from where he is being detained in Chicago. Her lawyers said Diogo spent his ninth birthday without his mom, and cried because he thought he was going home with her that day.
At some point soon, they will be going to Boston to stay with family, but their attorneys are not sure when they'll be able to leave Chicago.
As for the rest of the fight, the attorneys say there are many more families just like this that they are representing.
The Associated Press contributed to this report.