Monick Garcia, who has the mental capacity of a child because of a brain injury, walked away from the Caresource facility on Nov. 4 and had not been seen since then.
Her family issued a frantic plea for help on Eyewitness News Sunday night.
"Please help me find her," said Garcia's mother, Gail Zamora. "Please. I'm asking everybody to help me find my daughter."
Garcia, 36, was struck by a train about a year ago and left with a brain injury that made it difficult for her to communicate and required daily medication, her family said.
She went missing without a cellphone, money or medications.
After her story aired on ABC7 Sunday night, a nurse at Beverly Hospital in Montebello recognized the picture of a patient they had listed as Jane Doe. The nurse called the Caresource facility and confirmed it was Garcia.
It's not immediately clear how Garcia got from Granada Hills to Montebello, but the family was told she arrived at the hospital the day after she walked away from Caresource.
Los Angeles police are continuing to investigate the incident.