The biological mother contacted authorities after seeing the now 6-year-old at a birthday party and recognizing the child as her own.
Delimar Vera was thought to have perished in the 1997 blaze in her family's home, consumed by the heat and flames of a fast-moving fire blamed on an extension cord for a space heater. No body was ever found.
In January, the child's mother spotted a little girl at a birthday party and was certain she was her daughter, police Capt. John Darby said. A subsequent investigation prompted DNA tests that confirmed the mother's suspicion, police said.
After the DNA confirmation, the child's mother "didn't know whether to cry, to yell or to scream," Officer Manuel Gonzales said. "She just stood in shock. She was just in total shock."
Police have issued a warrant for the arrest of Carolyn Correa, 41, on charges of arson, kidnapping and conspiracy. She remained at large Monday; a telephone listing for her could not be found.
"This child, now 6 years old, who has been raised by Carolyn Correa as her own, is not her own," Darby said.
The girl's mother, Luz Cuevas, told WPHL-TV she recognized the child from a dimple on her face. "I said to my sister, 'Look, she's my daughter,'" Cuevas said.
"I feel so happy, you know, that I found my daughter," Cuevas told reporter Walt Hunter of CBS affiliate KYW. "One day, she'll call me mommy. You know. She'll say 'You are my mommy.'"
It was unclear what brought the child and her biological mother to the same party. State Rep. Angel Cruz, who helped the woman contact and work with police after she spotted the little girl, credited "motherly instinct" for connecting mother and child.
Ever since the blaze, the mother held on to the belief her child was somehow alive — partly because it didn't make sense a window in the infant's room was found to have been open even though it was the middle of December, Cruz said.
The little girl was placed in the custody of New Jersey Division of Youth and Family Services. It was not immediately clear when she would be reunited with her biological mother.