BACK in 2004, Nicola Sturgeon's SNP colleagues unkindly referred to yet another attempt to revamp her image as "Operation Human Being".
That snide remark was in keeping with her reputation as a "nippy sweetie" – another unflattering phrase that appeared to sum up someone once regarded as a rather irritable and humourless political machine. At that time, it was recognised within the SNP that the future Deputy First Minister was an ambitious and capable operator with a formidable intellect. What she lacked was the common touch and that slightly unctuous charisma that are seen as such assets for her boss and close colleague Alex Salmond.
Her seriousness and spikiness were seen as disadvantages in a political age where style so often triumphs over substance.
But now it is her substance rather than Salmond's style that is providing the reassuring hand on the tiller as the country struggles with a swine flu pandemic.
With data released last week indicating that swine flu is expected to infect 10,000 Scottish people a day by the autumn, the health secretary will have a demanding case load over the summer recess.
As she rises to that challenge with typical efficiency and a grasp of detail that one would not normally associate with Salmond – she is increasingly looking like future First Minister material. Men may be wary of her but women admire her businesslike approach, which may be a female vote-winner when the ballot box approaches.
But the feisty or even "nippy" approach with which she fights Scotland's corner when dealing with her London counterparts is just one aspect of a character that appears to have become far rounder as her political career has blossomed.
No longer are Sturgeon smiles as rare as a Salmond apology. And political observers have even noticed a nice line in wit. Journalists now look forward to the occasional lunch. Unlike some other politicians, she turns up on time and makes intelligent suggestions for articles.
Last summer, one veteran political observer took her out for lunch with some trepidation. "I was expecting an hour at the most. We ended up staying for three. She was really funny, droll and indiscreet. It was terrific fun," the journalist said.
"I told her that she seemed so much more relaxed. Her reply was: 'I've just stopped giving a f*** about what my critics think, I've grown out of it'." That sort of thing would never have been uttered by the slightly severe character who entered parliament ten years ago.
"In the past few years she's become more comfortable in her own ability. She believes in herself more than she used to," one colleague said.
After the demise of John Swinney's leadership, it was Sturgeon that the SNP turned to as they attempted to resurrect their fortunes. Salmond was leading the party from Westminster, but Sturgeon was doing the business at Holyrood.
"At least I look better in a skirt," was her war cry as she positioned herself as the glamorous half of the Salmond/Sturgeon double act while making a dig at McConnell's notorious decision to wear a trendy black kilt and vulgar Braveheart shirt in New York. Sturgeon would never have been guilty of such a fashion faux pas.
But in the run-up to the 2007 election she sought advice from the stylist Monica Loudon, who chose the outfits for her size 10 figure that stands around 5ft 6ins in her heels. "I thought she looked fantastic," said Loudon. "I kitted her out with clothes that she would have not normally gone for but she was very pleased. I would have to say that she has really kept it up without my help."
But, according to her friends, the most important factor in her transformation has been her relationship with her partner Peter Murrell. Before she and Murrell became an item, Sturgeon's love life had been the subject of scurrilous gossip. At one point she even felt compelled to explain to a tabloid newspaper the hurt caused by a totally unfounded rumour that had led to her getting the soubriquet "Gnasher".
Through the pages of a tabloid, she reassured a previously oblivious nation that she had never inadvertently injured an ex-boyfriend during houghmagandie.
Such are the travails of being in the public eye. But as she approaches 40, it is the stability provided by someone well outside the public gaze that has played such an important role in her change in outlook. Like Sturgeon, Murrell is fiercely political. But even though he is chief executive of the SNP, he can walk down the street without fear of recognition.
A calm, sensible man who shares her politics and her values, Murrell provides respite from her other great personal relationship – her working one with Salmond, a mercurial politician who demands much from his Cabinet.
Murrell, who is nicknamed Penfold as a result of an alleged resemblance to Danger Mouse's sidekick, is regarded as a supreme political tactician who is one of the unsung heroes of the SNP's rise to power. They first met around 20 years ago when Irvine-born Sturgeon was just 18. Sturgeon was attending one of the party's youth weekends in Aberdeenshire that Murrell used to organise.
Murrell was working in Salmond's Banff and Buchan office at the time. Their friendship was purely platonic in those days. Murrell kept working for the SNP and Sturgeon went off to train as a lawyer at Glasgow University. She worked as a solicitor at the Drumchapel Law Centre in Glasgow, but that did not curtail her political activities.
The fierce commitment that led her to join the party as an "act of rebellion" aged 16 continued to burn brightly as she nipped out of her office to speak on behalf of the party on the lunchtime news. As a teenager at Greenwood Academy, in Irvine, it was her anger over Margaret Thatcher's treatment of the Scots that led her to the SNP.
As her political star rose, she continued to bump into Murrell at SNP events but their friendship did not become deeper until later. They started working closely together in 2003 and there was great excitement within the Holyrood village when they were "outed" as a couple at the SNP conference in March 2004.
Now they live together in the east end of Glasgow in the Govan constituency – the seat with an iconic status for the SNP. There was great joy in 2007 when Sturgeon finally won it from Labour, a win that equalled the triumphs of Margo MacDonald in the 1970s and Jim Sillars in the 1980s.
Her newfound charm has not just been noticed by the political anoraks. It has made a good impression in the real world – most importantly with the health professionals she need to take with her if NHS reforms are to be pushed through.
"Not only is she always well briefed. She is always very pleasant and extremely amicable," said BMA spokesman Dr Dean Marshall. Operation Human Being appears to have been a success.
You've been Googled
• Sturgeon is reputed to have a shoe collection "to rival Imelda Marcos".
• According to one interview, her favourite celebrity men are: George Clooney, Joey from Friends and the Scottish actor Robert Carlyle, right.
• Of the Sex And The City girls, she thinks she is most like the demure lawyer Miranda, but has confessed that she admires the man-eating Sam. She said: "I love Sam because she's just so outrageous – she doesn't care. She just does what she wants to do and I admire her for that."
• Sturgeon joined the SNP in 1986 and became and Publicity Vice Convener. She first stood for election in the 1992 UK election in the Glasgow Shettleston constituency, and was the youngest parliamentary candidate in Scotland.
• In an interview, she once said: "When you're younger you take yourself far too seriously. Particularly being a young woman in politics where you feel a pressure to be taken seriously. If I was honest I was probably a bit po-faced. But the older I get, the less like that I am."