And a rather sonsie one at that.
With her younger brother James, she is the feisty joint managing director of the famous Edinburgh haggis-making empire, established in 1953 by her paternal grandparents and developed by her parents John and Kate.
Neither of her sisters is involved in the business, which she and James took over in the early 1990s when it wasn't yet turning over £1 million.
To say Jo - real name Johann - relishes her unique position as the sole female ambassador for the brand is something of an understatement. Being a woman in a man's world has positive advantages.
"I hated the name Johann because it was so unrhythmical and people were always getting the spelling or pronunciation wrong, so at age 12 I decided to become Jo. It's short and strong, and people initially think I'm a man - which gives me the upper hand, particularly in the butchery world where everyone's expected to be male," she declares.
Not only has she helped further elevate the ancient peasant dish immortalised by Robert Burns in his 1786 poem into a market leader with an anticipated turnover of £5.5m this year (up from £4.5m in 2013) and launching new 60th birthday versions of duck, grouse and pheasant, and another with venison and juniper (further new recipes are in the pipeline); she's also making it her personal mission to get haggis re-defined as specialist charcuterie, with year-round appeal, rather than a one-off seasonal oddity rolled out every Burns Night.
A UK-wide contract with Marks & Spencer has helped spread the word south of the Border, where consumption is higher than in Scotland.
"There's still confusion about what haggis actually is," says Macsween.
"At Burns Suppers, people see men in kilts, stabbing the beast and speaking solemnly in a weird Scots language, which both pulls them in and alienates them. Then on January 26, it's all put away for another year.
"I'd like to see our haggis displayed in supermarkets all year round, alongside black pudding and charcuterie, instead of next to the mince."
True to her word, she is addressing the haggis at a special Burns Supper at London's Borough Market next weekend and for the occasion, she intends to dump the usual Burns poem and write her own, suggesting it will be a "haggis haiku".
A keen networker for the cause, she is a member of the Vistage Group, the UK-wide coaching and support organisation for business executives, and feels it's "depressing" her Edinburgh branch is the only one with more women members than men.
Yet she refutes the suggestion she is a shout-out feminist. "I believe we're all a bit male and a bit female. Men have been conditioned to play down their female side and women have been conditioned to play up their male side. I know a lot of men who have a very high degree of femininity about them. That's why we haven't got so many things right in society; there aren't enough environments where men can be themselves.
"When it comes to board balance and good business, you need men to be free to tune in to their emotional intelligence. Talking about one's feelings leads to establishing core values in business. If you know what you stand for, you make much better decisions."
Throughout our interview she refers to her late father, and dedicated her book on haggis to "Dad, my great Chieftain".
When asked, she freely admits he was a "huge" influence on her life. "He was my mentor, my father, my friend. We really connected. Of course, you don't realise that until someone dies."
She married at 39, having met her husband Roger Duerden, an electronics engineer, on an online dating site in 2007 just months after her father's death at the age of 66. She has not taken her husband's surname.
"My career was and is massively important to me, but since I met Roger I've realised it's number two in my life instead of number one," she says. "I'd been trying to meet a man since early 2000 but they were all in London.
"People are so suspicious about internet dating but I fell in love with Roger just from reading his profile. It was well written and properly punctuated, and he made it clear he wasn't afraid of not being liked by everyone. He was into classical music, sang in a choir, was really cool about who he was. And he looked nice. I married him before I met him.
"That was six months after Dad died. One door shuts and another one opens. Maybe that had to happen."
T he potency of such life-changing events has not passed her by. She is deeply interested in the performing arts and attends Dark Angels intensive residential creative writing courses. Last year, at a personal insight workshop in Perthshire entitled The Stories We Tell, participants were invited to tell their stories, aided by drawing a line across the middle of a sheet of A4 and plotting the highs and lows of their lives so far either above the line or below it.
"Some people had dramatic zig-zags throughout, but mine was pretty flat up until 2006. Then I saw I had pinpointed both the highlight and the lowlight of my life at the same place - the time my dad died," she says. "At the age of 45 I suddenly saw my intense grief as a massive gift. I felt very strongly my father was going to live on in me; it was ancestral and deep. Now I know what people mean when they say people don't die."
I wonder where her mother is in all this. Her response is swift and unequivocal.
"Mum's still on the board. She's the visionary and without her, we wouldn't be here today. When the retail market was changing dramatically from independent shops to supermarkets (the arrival of Safeway in Morningside was the catalyst), dad - who had joined his father's butchery business straight from school - didn't want to know, but mum's response was to embrace the supermarkets and supply them. She saw their arrival not as a threat but as an opportunity, and turned the business on its head."
It was Kate, James and Jo who, in 1983, persuaded John to shut the family butcher's shop in Bruntsfield and start wholesale specialist production of haggis from new premises in Loanhead, where the company is still based.
"It was mum who wrote that first business plan, got the finance in place and engaged consultants to speak to the top 10 supermarket buyers. Immediately, eight out of 10 said they would buy it, including Selfridges and Fortnum & Mason.
"Mum and dad were a formidable force together. She always plays down her part but I don't want my mum ever to be written out of our story."
With sponsorship from Arts & Business Scotland, she recently launched an innovative storytelling project at the Macsween HQ to mark the company's 60th birthday.
All 60 members of staff were invited to contribute their experience of working there with a chosen object, and to present a second item that represented their life outside work. If they manage to attract further financial support, she hopes the material will turn into a public performance during 2014, a significant year for Scotland where several key events will bring more visitors than ever.
Rushing off to start composing her Haggis haiku, she says: "Did you know haggis is the top third internet search for visitors when contemplating a visit to Scotland? Even I had no idea of its pulling power."