Jayme Closs, 13, has been missing since her parents, James Closs and Denis Closs, were found shot to death in their home in Barron County.
Jamie Kaye Parker, 31, is accused of falsely claiming her daughter had non-Hodgkin's lymphoma, beginning in 2016 when the little girl was 7.
Matthew Phelps, an aspiring pastor, pleaded guilty to first-degree murder in her death and was sentenced to life in prison without parole.
“The 9-year-old made it clear that he wanted the man who killed his mother caught," the Clayton County Sheriff's Office said in a statement.
Footage from a Florida gas station shows a figure fitting Jayme's description traveling with two well-dressed, bearded adult males, authorities said.