In a statement, a Lutheran Services spokesman said Lady Flo died at 3.46pm on Wednesday at its Orana Aged Care Service, where she had lived since August 2014.

"She was surrounded by her family and loved ones including her sister Margaret Gilmour," he said.

"We safely entrust her into the hands of our Lord and Saviour, Jesus Christ.

"Until recently she actively participated as organist for church within the Orana community and other aged care facilities in Kingaroy."

Lady Flo, famous for her pumpkin scones, served as a Nationals senator in Canberra from 1981 to 1993 and was the wife of Queensland's longest-serving premier, Sir Joh Bjelke-Petersen.

Funeral arrangements were yet to be advised. Sir Joh died in 2005, aged 94.

Tributes have started flowing for Lady Flo with the Premier, Annastacia Palaszczuk, and Opposition Leader Deb Frecklington, among the first to publicly express their condolences. 

“On behalf of all Queenslanders, I want to express my sorrow and send my condolences to the family of Lady Florence “Flo” Bjelke-Petersen, upon reports of her death at 97 years,” the Premier said.

“Lady Flo, as she is fondly known, was the wife of Queensland’s longest serving Premier Sir Joh Bjelke-Petersen and brought her passions for cooking - those famous pumpkin scones - family and faith to the fore during Sir Joh’s 19-year service as Premier and 40-year service as a Member of Parliament.

“They were a loving couple and a formidable political pairing.

“Lady Flo represented Queensland in her own right serving as Senator from 1981 to 1993, and supporting many local and state-wide causes.”

Ms Frecklington said Lady Flo was “an outstanding and much-loved Queenslander who made a wonderful contribution to the community of Kingaroy, Queensland and Australia”.

“As a Senator for Queensland for 12 years, Lady Flo worked tirelessly for the betterment of rural and regional Queensland.

“She led a very full and successful life and was so-loved for her kindness, her genuine concern and care for others, her common sense and down-to-earth approach to life.

“Rest-in-peace Lady Flo. You were a rock of our community and will be sadly missed and lovingly remembered. I will always cherish your support and guidance.”