Her Senate district was located entirely in Montgomery County and included Vandalia, Riverside, Kettering, Centerville, Miamisburg and Germantown.

Having attended American University of Paris and graduating from Saint Mary-of-the-Woods College, Lehner was a three-term city councilwoman in Kettering, sat on the Ohio Ethics Commission from 1991 to 1997, served as a board member for the Greater Dayton Regional Transit Authority and has been active in efforts to address issues facing Dayton-area suburbs for decades.

Since Jacobson's elected successor Jon Husted was at that time serving as Speaker of the Ohio House, he was unable to resign and take his new seat in the Senate.

With incumbent and Speaker of the House Husted unable to run due to term limits, Lehner opted to succeed him.

On December 13, 2010, it was announced that the Senate Republicans had decided to appoint Lehner to fill the remaining two years of Husted's term.