Zahra was reported missing by her stepmother and father on Oct. 9, but police say no one outside of the family has reported seeing her since Sept. 25.
The girl had a grueling life. Stricken with bone cancer, she lost her left leg and much of her hearing. Relatives and neighbors said that Elisa Baker, was abusive to Zahra, who was often bruised.
ABC News' Yunji de Nies and Dean Schabner contributed to this report.