New York (CNN) -- A woman who stole an infant from a Manhattan hospital in 1987 pleaded guilty to a federal kidnapping charge Friday and could face at least 20 years behind bars.
Ann Pettway has been charged in the abduction of Carlina Renae White, now in her early 20s, who was reunited with her biological mother last year.
Pettway pleaded not guilty to the kidnapping charge last year.
Carlina White was 19 days old when her mother took her to the Harlem hospital with a fever more than two decades ago. The mother, Joy White, testified that she went home to rest and returned to the hospital to find her baby missing.
"Ann Pettway preyed on me," Joy White said Friday, adding that she remembered seeing Pettway at the hospital.
"All I want is justice," White said. "This is too much for me and my family."
The grand jury said Pettway had "willfully and knowingly" seized the baby. She turned herself in last month at the FBI office in Bridgeport, Connecticut.
"I raised her as my own and I knew it was wrong," Pettway said Friday.
The younger White, who was raised under a different name, long had a nagging feeling that she was brought up by a family she did not belong to, Ernie Allen of the National Center for Missing and Exploited Children has said.
CNN's Laura Batchelor contributed to this report