Sierra, Jasmine, and Jaden were abducted by their paternal grandmother Laura Vivas and her boyfriend in 2008.
Vivas took the children and hid out in Mexico.
But marshals were recently able to hunt them down using phone records.
During their disappearance, the children's mother, Leanna Dinkens, was devastated, but she never gave up hope.
"I felt like I was at a funeral. I felt like my girls were gone," said Dinkens.
Vivas is being held on bond and faces up to six years in prison. Her boyfriend, Javier Vargas, remains at large in Mexico.