Hinkfuss was born on September 30, 1931 in Lima, Ohio. She later graduated from Cardinal Stritch University. Hinkfuss went on to serve on the board of Premontre High School and is one of the Directors Emiriti of the Green Bay Packers.
Hinkfuss was first elected to the Assembly in 1988. Additionally, she was a member of the Green Bay, Wisconsin City Council and a Brown County, Wisconsin supervisor from 1974 to 1982. She is a Democrat.