Twenty-two-year-old Avery Bourne is the youngest lawmaker to serve in Illinois.
The Republican from Pawnee previously worked for Congressman Rodney Davis, who says he is confident she will be willing to make tough decisions.
"I as a candidate last year was ridiculed for waging a war on women. You know what? I'm pretty proud to have a young leader like Avery Bourne as my state representative."
Bourne was appointed to fill a House seat left empty when Wayne Rosenthal left to head the Illinois Department of Natural Resources. She was going to law school at Washington University in St. Louis, but will drop to part time and take a leave of absence.
Previously, now-Congressman Aaron Schock of Peoria was the youngest member to serve in the state legislature. He was 23 when he won a contested race for his seat.