She was last seen asleep in her bedroom at about 2:30 a.m. Saturday, according to her parents.
Zahra's father, Adam Baker, told "Good Morning America" Monday that he hadn't seen his wife much since police were called. He admits it was possible that his wife was involved in the disappearance.
Elisa Baker, Zahra's stepmother, has been arrested on unrelated charges. She has not been ruled out as a person of interest in the case.
Police say the stepmother's account of the hours before the 10-year-old disappeared shows inconsistencies.