Prior to election into politics, her education included a Certificate in Real Estate Sales, Political Studies undertaken by correspondence from Papua New Guinea through the University of Queensland, and was a Classified Teacher from the Wattle Park Teachers College, Adelaide.
Penfold is a fellow of the Flinders University of South Australia Foundation Inc. and Member of the Eyre Peninsula Agricultural Research Foundation as well as Patron of the Lower Eyre Peninsula She has also been a member of many economic, marine and arts organisations, and has participated in hospital and health fundraising.
The 2006 election saw Penfold face a National candidate on the two party preferred vote.
Penfold held Opposition portfolios of regional development, small business and consumer affairs.
Former Australian Farmers' Federation Grains Council chairman Peter Treloar won the seat for the Liberals with a collapse in the National Party vote causing the two party preferred vote being between Liberal and Labor candidates.