SAN JOSE LAS FLORES, Guatemala (AP) -- The mother of a Guatemalan boy whose body was found in the desert about a mile from Texas' southern border said Tuesday she begged him not to make the dangerous journey from their modest cinder block- and sheet-metal home high in the northern Cuchumatanes mountains. But Cipriana Juarez Diaz, ailing and bedridden, said her son Gilberto told her he wanted to earn money to help her. "I told him not to go but he wanted to help me get rid of my illness," Juarez Diaz, who has epilepsy, told The Associated Press on Tuesday. She said she draped him with a white rosary as he left. "He was a good son," she said. "I just hope God gives me the strength to bear seeing his body when they bring him to me." Gilberto Francisco Ramos Juarez was found with the rosary still around his neck and a brother's Chicago phone number scribbled on the inside of his belt buckle about two weeks ago. He was alone in brush less than a mile from the nearest U.S. home, a South Texas sheriff said Monday. He apparently got lost on his way north and likely died from the elements. An autopsy did not find signs of trauma. His birth certificate says he was 11 years old. But his father, Francisco Ramos Diaz, said Tuesday that the boy was really 15. Ramos Diaz said Gilberto's birth certificate carried the birth date of his younger brother because it took the family several years to register him. Because the parents couldn't remember the exact date of Gilberto's birth, they gave the same date for both young sons, who became listed as twins. While hundreds of immigrants die crossing the border each year, the discovery of Gilberto's decomposed body in the Rio Grande Valley on June 15 highlights the perils unaccompanied children face as the U.S. government searches for ways to deal with record numbers of children crossing into the country illegally. Hidalgo County Sheriff Eddie Guerra said he was the first child immigrant his office has found since he became sheriff in April. More than 52,000 unaccompanied children have been apprehended entering the U.S. illegally since October, creating what President Barack Obama has called an "urgent humanitarian situation." On Monday, Obama asked Congress for more money and additional authority to deal with the surge of youths, mostly from Central America. Obama wants flexibility to speed the youths' deportations and $2 billion to hire more immigration judges and open more detention facilities. The number of unaccompanied immigrant children picked up along the border has been rising for three years as they fled pervasive gang violence in Honduras, Guatemala and El Salvador. More recently, children and parents have said they heard children traveling alone and parents traveling with young kids would be released by authorities and allowed to continue to their destination. Many of the children turn themselves in to the first law enforcement person they see, so Guerra said it was unusual to find a child in this more remote area -- near La Joya, about 20 miles west of McAllen. Sometimes smugglers, known as coyotes, leave people behind if they can't go on; other times a group may scatter when authorities approach.