[1] Sheldon was born in Bundaberg, Queensland, and attended St Bernadette's Primary School and Soubirous College.
[2] A long-time member of the Liberal Party, she contested and won preselection for the National-held seat of Landsborough upon the 1990 resignation of former Premier Mike Ahern.
[7][8] She subsequently served as Shadow Treasurer under Borbidge in the lead-up to the 1995 state election, which resulted in a one-seat victory for Labor.
Sheldon was thus sworn in as Deputy Premier and Treasurer under Borbidge and became the first woman in Queensland to hold these roles.
[9] After the Borbidge Ministry lost office after the 1998 election Sheldon stood down as Liberal leader, with former deputy David Watson succeeding her.