A quarter of a century ago, when I covered Scottish politics for The Sun, a young lady came to see me to talk about her hopes for election.

I'd not met her before but found her polite, serious, intelligent and quietly confident.

It was immediately clear that this 21-year-old, standing in the 1992 Westminster election for the SNP in the then-hopeless seat of Glasgow Shettleston, was something out of the ordinary. Her name, as you have probably worked out by now, was Nicola Sturgeon.

A lot of water has gone under a lot of bridges since then. Now we have Nicola the First Minister who has been thoughtfully formed into Nicola the Brand. A measure of the success of this is that to millions, she is now just plain Nicola. No addendum to that one word is necessary.

But who exactly is this remarkable woman, rated second most powerful female in the UK recently by Forbes magazine, who is easily the most competent and impressive politician across these islands? That's a harder question to answer than you might think.

After having observed her, talked to her and worked with her over that 25 years, I know Nicola Sturgeon pretty well. And yet, like many, I hardly know her at all.

In many ways, she is a mass of contradictions. For a start, there are two Nicolas: the personal and the political. The first is more opaque. Even those who claim to be close to her will admit that they don't actually know much about her beyond the impressions she chooses to place in the public arena. Selfie queen; Andy Murray fan; X-Factor devotee; hopeless cook -- these are all players into a carefully cultivated narrative.

Individually and collectively, they help to give substance to the message that she's really One Of Us, just like you and me. That she's naturally and genuinely empathetic and understands our concerns and problems. In fairness, much of this is true.

Another contradiction is that she's really quite shy, a character trait which sometimes makes her seem distant. At the same time, she can be very funny and her humour quite ribald. And she has genuine warmth: When my wife had a cancer scare a couple of years ago, Nicola came over, asked how she was and put her arm round her. It was a generous and thoughtful move which was appreciated.

She doesn't make trusted friends easily. Indeed many thought to be close pals admit privately that they're not really that close at all. And at least one veteran cabinet secretary has admitted to me that they really don't know much about her.

So who actually are the Sturgeon confidantes, the people whom she turns to for comfort and heartfelt advice? Unsurprisingly, it's her family and most particularly her husband Peter Murrell, who also conveniently happens to be chief executive of the SNP. It's inconceivable that she would take any major policy decision without talking to him first.

If the Personal Sturgeon is challenging to deconstruct, the Political Sturgeon is less so. She's been in government and the public eye for nearly a decade and opposition leader in the Scottish Parliament before then, so we've a pretty clear picture of how she thinks and works.

Nicola's rhetoric and reality have long been different. She positions the party as radical, forward-thinking and decidedly left-of-centre. In fact, she is cautious, centrist and politically small-c conservative.

This is by no means a criticism. By and large Scotland is not a politically adventurous nation universally signed up to a socialist experiment. So Nicola sits quite well with the broad mass of opinion (it's one reason why she and the SNP are so popular).

That she is competent, focussed and able to connect intuitively with the Scots psyche is beyond doubt. She is also highly adept at reading the runes. For instance, she really didn't display much of an interest in Europe before the Brexit campaign and vote. Now, as the British constitution is under attack from a self-constructed trebuchet, Brussels has been promoted to the centre of her agenda.

This isn't to suggest that she's being cynical -- she's always been a supporter of the EU -- but rather that it wasn't a priority before and could be allowed to rumble along by itself. Dramatically changed circumstances mean it has become front and centre, and she's seen the opportunity in that.

Sturgeon continues to be popular and trusted by the public to a degree that is remarkable for any modern politician. After nearly two years as First Minister, her honeymoon shows little sign of ending. Indeed, the strength of the SNP under her stewardship is such that winning 63 seats at May's Holyrood election was billed by some commentators as a failure because the party fell two seats short of a majority.

However, she does need to be careful. When you're at the top of the mountain, the only way is down, and there are a number of slippery ice pockets beneath her feet. She faces accusations that she has so far done little by way of strategy development -- in SNP land, policy and economic think tanks are somewhat thin on the ground. While she's brilliant at presentation, she's not proved to be visibly strong on these other issues.

Accusations have also been made that she and her predecessor Alex Salmond have turned Scotland into a one-party state. This is preposterous, especially when she no longer controls the parliament. The claim that arrogance has crept in does, however, have some substance, the latest instance being the fact that ministerial parliamentary liaison officers are allowed to sit on Holyrood committees pertinent to the portfolios of their ministers. This clearly flies in the face of parliament's independence and proper government oversight and scrutiny.

And there's plenty else on the radar to cause her trouble. Police Scotland continues to behave dysfunctionally. The Named Persons legislation has been badly managed, in fact appallingly so. The Offensive Behaviour at Football Act looks about to be put to a firing squad. And we don't really know what her much-heralded new independence initiative means or when it will start, any more than we know what Brexit means.

Which brings us neatly to Nicola's biggest challenge: Indyref2. In the febrile hours after the EU referendum vote, she famously said under questioning that she thought another referendum on independence was "highly likely". I suspect she now regrets those words, as they have created a rod for her own back and a stick for her opponents to beat her with.

The unexpected Brexit result has placed her between the hammer and the anvil. If she delays or kicks the idea of another independence vote into the long grass, she will risk alienating the party, and most particularly the 100,000 or so who have joined since 2014. Independence is the SNP's whole reason for existence; rejecting any opportunity to seize it would be a risky and precarious move for her.

So, though, is the alternative of seizing the moment and calling a referendum. With the polls apparently not having shifted much since the first indyref, this would be an even more risky win-or-die strategy. Score a victory, and she will become a politician of truly global stature, writing herself forever into Scottish history. Lose again, and she will be gone by the next morning, her political career a shredded carcass for the vultures to feed on.

Nicola Sturgeon is not a gambler. The serious, scholarly 21-year-old I met all that time ago has grown in political skill, respect and stature. But she is still a cautious, quiet thinker who relies on instinct and common sense rather than on impetuous bravery.

The First Minister I know may hold the dice but she is unlikely to throw them. Indyref 2 might come eventually, but it's probably years away. Despite the rhetoric, she is more likely to spend her time shaping domestic policy, finally working up a vision of what she wants Scotland to be and hopefully making this a kinder, gentler, less belligerent country.

And you know what? In that, she's very probably right.

Comment by Andrew Collier. Andrew is a freelance writer and broadcaster covering Scottish politics, business and religion. A former Scottish correspondent of the Sunday Times, he has just returned to journalism after working for five years as a communications strategist for the SNP. He was also a speechwriter for Alex Salmond and Nicola Sturgeon.