(CNN) More than 1,000 miles from the river bank where the bodies of her son and granddaughter washed ashore , Rosa Ramírez wept.

At her home in San Martín, El Salvador, Ramírez clutched what she said were some of Angie Valeria's favorite toys -- a baby doll and a stuffed purple monkey, holding a heart.

The devastating photo of 23-month-old Angie Valeria and her father Oscar Alberto Martínez floating in the Rio Grande is a grim reminder of harsh realities at the southern US border. It's shaken viewers around the world

The image shows a heartbreaking end to a harrowing journey.

Months before the river's rushing currents claimed their lives, and months before a photographer's shutter captured the searing image of their death, Ramirez said she tried to convince her son and his family not to make the dangerous trek north.

"As a mother, you don't want your children to be so far away," she said. "But...the idea of leaving had gotten into their heads."

Oscar had been working as a cook in a pizzeria while the family lived with her in San Martín, a municipality in central El Salvador just east of the country's capital.

They wanted to have their own home, Ramírez said.

"That," she said, "was what motivated them."

Ramírez told CNN en Español that the death of her son and granddaughter has forever changed her. She's turning to God and religion for strength.

"Nothing can fill this emptiness," she said. "But at least this gives me strength to cope."

José Martínez said he'd spoken on the phone with his son just days earlier, on Friday.

"He had already been in Mexico for a few days, and everything had been going wonderfully," Martínez said.

Oscar Alberto Martinez, his daughter, Angie Valeria, and his wife, Tania Avalos.

But in reality, conditions in Matamoros, Mexico, the border city where the family had been waiting to present themselves at a US port of entry and seek asylum, were more difficult, according to La Jornada , the Mexican newspaper that first reported the story of the father and daughter's deaths.

At the end of May, more than 2,000 migrants were waiting "in conditions of hunger and overcrowding" there to seek asylum at ports where, according to La Jornada, US agents granted an average of three appointments per week.

Tania Vanessa Ávalos, Oscar's wife and Angie Valeria's mother, told the newspaper her family had grown increasingly desperate as temperatures reached over 110 degrees. They had been in a migrant camp in Matamoros since Sunday, the newspaper said, citing Ávalos.

José Martínez said he had spoken on the phone with his son just days earlier.

That's when Oscar made a fateful decision. Instead of waiting any longer, they would cross the river into the US.

"Óscar Alberto took Valeria in his arms and entered the water; he swam to other side and reached mainland, where he left his daughter. Immediately after, he returned and went for Tania," La Jornada said. "However, in an instant he realized that the girl, after seeing that he was getting away, threw herself into the water. Óscar Alberto returned and managed to get a hold of the little girl, but a strong current dragged and sank them."

Speaking to reporters in El Salvador as they tried to piece together the devastating news, Rosa Ramírez and José Martinez recounted what they'd heard about the tragedy.

Ramírez said her son died while trying to save his daughter's life.

A previous version of this story indicated the family had been at a migrant camp in Matamoros for two months. In fact, they were in Mexico for two months but arrived at Matamoros Sunday.