Julie Bishop has turned down the chance to become South Australia's next governor, with her sister saying the high-profile former minister did not want to become a "glamorous public servant".

Key points: Ms Bishop's sister said the former minister was approached by SA Premier Steven Marshall

Ms Bishop's sister said the former minister was approached by SA Premier Steven Marshall She said she would have done an "amazing job" but wants to pursue a private sector role

She said she would have done an "amazing job" but wants to pursue a private sector role Current Governor Hieu Van Le's term is due to expire in August

Ms Bishop quit ahead of the federal election, after being relegated to the backbench following last year's Liberal leadership spill which saw Prime Minister Scott Morrison take on the top job.

Her sister MaryLou said Ms Bishop was approached last year by SA Premier Steven Marshall about taking up the position.

"It was spoken about, probably about last September," MaryLou Bishop told ABC Radio Adelaide's David Bevan.

"Julie and Steven get on really, really well.

"They started to think 'she's not going to stand again' and started putting out feelers and right from the word go she said 'I do not want the job'.

"I would have loved her to have been governor. She would have done an amazing job. However, I know why she said 'no', I understand completely."

Ms Bishop was born at Lobethal in the Adelaide Hills and attended St Peter's Girls' School in Stonyfell, east of Adelaide.

She studied law at the University of Adelaide before working as commercial lawyer in Perth.

She went on to become an MP for more than 20 years, representing the seat of Curtin in Perth.

Her sister said Ms Bishop, 62, had "another 10, 15 years of freedom ahead of her" before she would consider such a position.

"She would have been, in another word, a public servant. It might be a glamorous public servant, but nevertheless you are answerable to the government of the day," MaryLou Bishop said.

"She's got another career ahead of her, she wants to prove herself in the free market, in private enterprise.

"Let her fly, let her do what she has to do, let's put another governor in place, whatever, and perhaps come back to her in 10 years' time when she's in her 70s, early 70s. She's amazingly fit, she doesn't look her age."

Ms Bishop was approached after last year's leadership spill, her sister said. ( ABC News: Nick Haggarty )

The current SA Governor, Hieu Van Le, is due to conclude his five-year term in the role at the end of August, after he formally took up the position in September 2014.

In a statement, a South Australian Government spokesperson did not say who was likely to take on Mr Van Le's position.

"There's no doubt Julie Bishop is a great South Australian," the spokesperson said.

" … His Excellency the Honourable Hieu Van Le is doing a fantastic job in this important and prestigious role and is well respected across our state and by the Government."