Pamela Graham, 48, Rilya's legal custodian, told jurors that Geralyn Graham, no relation to Pamela, kept the girl tied to her bed to keep her from misbehaving.
For punishment, Geralyn once put the girl into scalding bathtub water, Pamela Graham told jurors.
In December 2000, Pamela said she came home from work and Rilya was gone. But Pamela said she didn't report any of these incidents to the police because she herself was afraid of Graham and was "weak."
The Miami Herald said Geralyn Graham, 66, is on trial for the death of Rilya charged with first-degree murder, kidnapping and aggravated child abuse.
The Herald reported the case has caused an outpouring of criticism of Florida's Department of Children and Families, who supervised Rilya.
DCF did not notice Rilya was missing for more than two years after a case worker neglected to supervise the child.
Geralyn allegedly confessed to the crime to a cellmate, who may testify this week, the newspaper said.