Ciara DeRyke, 26, faces up to a year in prison if she is found guilty of obstructing the investigation by Effingham County sheriff's deputies, KSDK-TV, St. Louis, reported.
The body of Willow Long, DeRyke's 7-year-old daughter, was found Sept. 9, wrapped in plastic bags and secured with duct tape, near Watson in Effingham County, a rural area in the southern part of the state. Her mother had reported her missing a day earlier.
DeRyke's brother, Justin, 22, allegedly told police that on Sept. 7, a Saturday, he had been watching Willow and her younger brother while their mother was out with friends. He said Willow scratched him and then ran away, impaling herself on a stick accidentally.
Justin DeRyke said he cut Willow's throat because she was in pain. He has been charged with first-degree murder.
Investigators say when Ciara DeRyke first called police she said her daughter disappeared while she was taking a nap Sunday and that she had seen Willow that morning.
Bail was set at $75,000.