Ms Rein might have quietly demonstrated this was no joke.

On Tuesday, she sold the multinational business Ingeus, which she built from scratch while raising three children, to Arizona's Providence Service Corporation in a deal worth up to $222 million.

The US firm will initially pay $62 million in cash for the business, which offers work placement and other services in 10 countries. But it could pay up to $160 million more in cash and shares depending on future performance.

As the owner of 50 per cent of the British business and 95 per cent of the Australian parent, Ms Rein stands to earn up to $150 million, in cash and shares, making her indisputably one of Australia's wealthiest women.

Ms Rein founded Ingeus in 1989 in Brisbane, to assist injured workers or people with health conditions to return to work.

In interviews, Ms Rein cited her father as her inspiration. A Paralympian, he retrained as an aeronautical engineer, played wheelchair basketball and won gold for Australia in the Paraplegic Games.

''In my experience, only a very tiny percentage of people really don't want to work,'' Ms Rein said in one interview. ''Like my father, a vast majority of people want to be contributing and participating members of the community, once they see what's possible for them, once they can see a way through the myriad problems they may face.''

But in a twist of fate it was former prime minister John Howard, the man her husband ousted in 2007, who created the greatest opportunity for Ms Rein.

In 1997, Mr Howard announced

policies to outsource the job placement functions of Centrelink, creating a huge opportunity for both commercial and not-for-profit agencies. Ingeus became one of the biggest companies.

In Britain, former prime minister Tony Blair followed a similar path, with a welfare system based on mutual obligation, which meant welfare payments were accompanied by an obligation to get back to work. Ms Rein set up a business there in partnership with Deloitte UK and Ingeus prospered. In 2011, the Cameron government introduced the Work Program, and Ms Rein's company is now the largest employment services provider in Britain, and 70 per cent of the firm's revenues come from British operations.

Ingeus is in France, Germany, South Korea and Saudi Arabia and has a staff of more than 2500 in 10 countries, its website says.

Last year, Ms Rein stormed into BRWs inaugural list of the top 10 richest women in Australia at sixth. The magazine estimated her wealth at $210 million.

But it has not all been plain sailing. The spectacular success of Kevin in '07 meant Ms Rein had to take some hard decisions. In order to avoid any perceptions of conflict of interest, given her business's dependence on government contracts, she decided to sell her Australian operation. But she continued running the global business from Brisbane.

''I wanted to do my best as first lady and I also wanted to keep contributing at work,'' she explained at the time.

If the constraints imposed by her husband's ambition ever rankled, Ms Rein hid it well.

''The opportunity of serving as the wife of the prime minister, that was an enormous honour … and I wouldn't have missed that for the world, but I'm really enjoying what I do now,'' she said in one interview after Mr Rudd lost the leadership.

It might not have sounded like the words of a feminist.

But perhaps Ms Rein is the ultimate role model - a woman who has balanced family, an ambitious husband and her own career.

Ms Rein will continue as managing director of Ingeus for at least five years, reporting to the Providence chief executive.