RICHMOND, Va. -- A two-year-old Virginia girl who police believe was killed by her stepmother died from dehydration, an autopsy showed.

The Richmond Medical Examiner's office said Tuesday it ruled Ariellisa Simmons' death as homicide by dehydration, CBS affiliate WTVR reported.

Her stepmother, 35-year-old Andrea Watkins-Simmons, was indicted by a grand jury last week on charges of first-degree murder, felony murder and child neglect.

The child's remains were located inside an attic of a vacant apartment in January, multiple police sources told WTVR. Police have yet to confirm the identity of the remains discovered in the attic.

Watkins-Simmons was reported missing in November and police said at the time that they believed Ariellisa was with her.

Richmond police said Watkins-Simmons was arrested in New York in late January on a charge of felony abduction and was returned to Virginia last week after fighting extradition.

She is being held without bond at Richmond City Jail and scheduled to appear in court on May 2.