More broadly she has no doubt that the work environment for women has improved greatly - she's lived through that change.
Despite leaving school at 16, getting married at 19 and becoming a mum on her 21st birthday, she currently chairs the boards of The Warehouse, Auckland Airport and Mercury Energy, and stepped down from TVNZ earlier this year. She's also a director at ANZ and was chief executive at Fairfax New Zealand until 2009.
In her new book A Woman's Place she tells the story of how she achieved her rise to the top of the corporate world and offers some advice for those coming through the ranks.
- Read an extract from A Woman's Place by Joan Withers
Stuck at home as a housewife in the 1970s, Withers bought a Bernina knitting machine and learned to make jerseys to earn what was then called "pin money".
"The expectation in the 70s was that women would stay home - while the children were at pre-school and then go back potentially - that was the expectation I had," she says.
"I wasn't someone who was brought up to be ambitious or to have big aspiration either academically or career wise. I was going to stay home with Jamie [her son]. I really became conscious a few years down the track that a big part of life was passing me by."
Withers eventually went back into the workforce as a part-time sales rep and copy writer for Suburban Newspapers and rose through the ranks to a senior management position.
Backed by the company, she did an MBA and then moved to a smaller organisation (private broadcaster Radio i) as chief executive, to put her new knowledge into practice.
"I'm not ambitious," Withers says. "I think it's because people keep giving me promotions and opportunities that I've felt an enormous responsibility to do the best I possibly could. Equipping myself by getting the degree was another way of achieving that."
But she remains conscious of the challenge many women face as they seek to juggle career and family.
"The challenge for employers is making sure women don't drop out because it becomes too tough or they believe there are too many compromises to be made."
The percentage of female directors is changing, she says.
"I think that's really important because it's having women around the board table who look to the CEO - almost invariably a male - and say what are you doing in terms of assessing your direct reports ... are you getting diversity within that pool?"
There was good work going on through a number of initiatives driven by both male and female business leaders, she says.
"The business case for diversity is irrefutable so we've got to do better. We've got to start seeing the numbers change or we risk a future government coming in and saying, 'We're going to impose quotas', which I think would be a negative step."
Withers says she has written the book to offer some advice and inspiration for those trying to juggle the challenges of a busy career.
"I'm not saying you can have it all in the sense that everything's a bed of roses. But I hope that what my story shows is that you can have a balanced lifestyle, you can have a great relationship and enjoy things outside the corporate world and still be successful."