The body of Nalani Johnson turned up at Pine Ridge Park in Indiana County, 37 miles east of Penn Hills, where investigators said she'd been kidnapped, Indiana County District Attorney Patrick Dougherty said at a news conference.
Sharena Islam Nancy, 25, faced kidnapping and other felony charges. She was arrested Saturday, police said.
“We believe she is involved,” Dougherty said. “To what extent, that is still to be determined.”
An autopsy is scheduled for Wednesday, Dougherty said.
Investigators said Nancy was romantically involved with the child's father, Paul Johnson.
In an interview with police, Nancy said Johnson sold his daughter for $10,000, The Pocono Record reported.
A criminal complaint said Nancy told interviewers that Johnson ordered her to drive the child to a woman who would take her.
Johnson denied the allegations.