According to the Riverside County District Attorney's Office, 30-year-old Riverside resident Susan Marie Rank is accused in the death of the child, identified by family members as Zayla. Rank's arraignment hearing Wednesday was postponed to Feb. 13.
Along with the murder count, she is charged with a sentence-enhancing allegation of using a deadly weapon in the commission of a felony.
Authorities were first alerted to the incident with a phone call around 6:45 a.m. Friday. Sheriff's deputies responded to a sober-living group home in the 3400 block of Cannes Avenue and discovered the girl's body outside the residence.
Everyone at the house was immediately detained, including the homicide suspect, authorities said. Susan Rank is being held on $1,000,000 bail.
Coroner's officials said an autopsy has been completed but the official cause of death will not be released for several weeks, pending lab results.
In interviews with ABC7, relatives said Susan Rank was born with a brain tumor and is mentally ill. The victim's grandmother and great aunt say they believe Rank is responsible for the child's death.
The family later launched a fundraising effort to help pay for Zayla's funeral expenses.
"Our family is heartbroken," Tracylyn Sharrit wrote on a GoFundMe page. "My sister is in deep mourning over the loss of her grandbaby, and the fact that it was at the hands of her mentally ill daughter weigh heavy on her heart."
City News Service contributed to this report.