Mary Lou McDonald first made an impression in national politics in November 1998 when she spoke at her party's árd fheis in the RDS.
The 29-year-old Trinity College graduate of English literature and resident of the leafy Dublin suburb of Castleknock was just the kind of articulate young middle-class woman her party was looking for. She stood at the rostrum and spoke passionately about the need for reform of the RUC in the North.
At this time in her political career, Mary Lou's leader was Bertie Ahern, and the young delegate from Dublin West and treasurer of a local cumann was an active member of Fianna Fáil.
The world seemed to be at her feet in a party that was on a roll.
It was hoped that she might run in the following year's local council elections and she was offered what was deemed to be a safe seat.
In Fianna Fáil she is now seen by some as the one who got away. Senator Mary White, who worked closely with her in Fianna Fáil at that time, told Weekend Review: "It was clear to me that she was talented."
Mary Lou's middle-class family from Rathgar in South County Dublin were staunch Fianna Fáilers.
But it also became apparent that she did not quite fit into the party.
Bertie Ahern noticed her at the time and told an acquaintance later: "She kept banging on about the North."
Mary Lou's politics were a good deal more green than those of Fianna Fáil and within months of the árd fheis the promising young party member had defected to Sinn Féin, where she very quickly became the rising star.
She seemed to follow Gerry Adams to every photoshoot and was always on his shoulder. This role led some not to take her seriously and she was caricatured as a "pouting puppy in Sinn Féin's pound of scruffy mongrels" and the "leader of Sinn Féin's millinery wing".
This week, Mary Lou returned to the RDS, scene of her Fianna Fáil debut, as queen of all she surveyed. Her protegé Lynn Boylan, as far removed from the traditional image of a Shinner as she is herself, topped the European poll in the Dublin constituency and was held aloft.
It is a chilling thought for those detractors who remember IRA atrocities such as the murder of Jerry McCabe.
But in some radical chic circles, such memories are best swept under the tastefully patterned carpet and forgotten about. Mention of the Troubles is as welcome as an unkempt ghost at a dinner party.
ADRIAN Kavanagh, lecturer in political geography at NUI Maynooth, has analysed the election results and believes Sinn Féin could win up to 30 seats at the next general election.
This could give them the choice to join a coalition government from a position of strength, with Mary Lou as the likely Tánaiste, or bide their time until the following election when she could have a genuine tilt at becoming Taoiseach.
So how did the privately educated girl from upmarket Rathgar end up as the party's southern icon, an instantly recognisable figure, with whom every Sinn Féin election candidate or party worker wanted to pose during the campaign?
Early on in her career, she certainly did not play up her well-to-do background – and her south county lilt is overlaid with a hint of a Dub drawl.
But now she seems more comfortable with the image of the hard-working middle-class mum.
When she was tracked by Ursula Halligan for a TV3 documentary on Sinn Féin, she was quite happy to be filmed shopping for prawns in her local Superquinn in Blanchardstown shopping centre.
Short of asking for smoked salmon, she couldn't have done more to fit in with a certain radical chic stereotype.
And when she was discussing an article of faith of the Sinn Féin brand of republicanism – a united Ireland – she broke off to say she was looking for Cheerios: "Cheerios and a united Ireland."
The flippant tone seemed to suggest that, for the new sweetened Cheerios wing of the party, a United Ireland might not be as important as it once was.
Margaret Thatcher promoted herself in a similar fashion, as the ordinary woman out shopping. But Maggie probably wouldn't have bought prawns.
Mary Lou is now keen to emphasise the social mix in the party.
While the Adams generation educated themselves in prison cells, the new intake – the so-called 'lilywhites' – have university degrees.
Lynn Boylan went to UCD while her partner, Eoin O Broin, another senior party aparatchik, was educated at Blackrock College.
Mary Lou's father, Patrick, was a successful surveyor, married to Joan. She has two brothers: Bernard, a scientist, and Patrick, a patent lawyer. Her sister, Joanne, is much more radical than she is as a member of the militant republican fringe group Eirigí.
By all accounts, Mary Lou showed little interest in radical politics at school at Notre Dame des Missions, a girls convent school in Churchtown. However, she did show an interest in debating. She has said her childhood idol was John Lennon and her favourite subject was English.
The studious convent girl was an academic high achiever, leading her to Trinity College and postgraduate education at the University of Limerick.
In the Mary Lou story there is said to have been a 'road to Damascus conversion' as a 12-year-old when she followed news of the hunger strikes on television.
There was also a strong memory in her family of her mother's uncle, James O'Connor, who was executed by Free State forces in the Civil War.
These events may have influenced her views, but they did not seem to incline her to support the IRA's armed struggle. The TD Finian McGrath remembered her attending a forum on Northern Ireland in the early 90s and talking about the need to pursue "peaceful and democratic means".
Mary Lou seems to have hooked up with Sinn Féin when she took an interest in disputes over Orange marches on the Garvaghy Road in Portadown.
Some Fianna Fáilers believe she made the leap to Sinn Féin for "careerist reasons", because there were more opportunities in the smaller party, but most of those we spoke to believe it was a genuine matter of principle.
Initially, as a middle-class Trinity graduate, she was greeted with suspicion by some of the old-fashioned die-hards in Sinn Féin.
Killian Forde, a former SF councillor who worked as her personal assistant when she was elected to the European Parliament, says: "She probably rose too fast in Sinn Féin. Because she hadn't worked too much at grassroots level, she didn't have much understanding initially of how politics worked.
"She was always a very good media performer, but didn't have much understanding of economics. I think she is a much slicker performer now and masters her brief.
"It was a bit of a nightmare for her when she was in the European Parliament, because she had small children, and she was also heavily involved in running Sinn Féin."
She met her husband Martin Lanigan, a gas control superintendent in Bord Gáis, before she joined the party.
Although Sinn Féin TDs live on the average industrial wage, he would draw a healthy income from his job, and it was recently reported that he will receive a substantial cash windfall of up to €65,000 from the privatisation of Bord Gáis.
After starting her career in the Castleknock area, Mary Lou moved to Cabra in the heart of her political base of Dublin Central.
The couple bought a modest bungalow on Cabra Road, but redeveloped the site into a more stately two-storey residence . It is an impressive structure that stands out on the street and it was dubbed "Mary Lou's own White House".
Those who know her say she works extremely long hours.
One acquaintance said: "She likes to drive her children to school early in the morning and might still be in a TV studio being interviewed by Vincent Browne at 11.30 at night."
Mary Lou was Lynn Boylan's campaign manager for the successful Euro campaign. The young Dublin candidate had previously run as Lynn Ní Bhaoighealláin. It said much of Sinn Féin nua's political expedience that the gaelicised name was dropped for the campaign, placing Boylan at the top of the ballot paper.
It is commonly assumed that Mary Lou will take over as leader of Sinn Féin, but close observers of the movement believe that this will take much longer than people think. It may not be after the next general election.
"Only fools and wishful thinkers believe that Gerry Adams will stand down or be pushed in the party," says Henry McDonald, author of Gunsmoke and Mirrors, an account of the Troubles. "There is no one inside Sinn Féin who would dare to steal the crown from him. Apart from the cultish devotion to him, they wouldn't have the guts."
Although she is the star media performer in Sinn Féin, Killian Forde doubts that she has the organisational nous of Adams and his strategic ability to always look three steps ahead.
Mary Lou's cohorts in the South have enjoyed unprecedented electoral success by peddling a vague, populist, left-wing philosophy that is low on specifics and promises not to frighten the horses.
They claim to be able to redistribute wealth in the country, without even imposing a tax on the most important asset of all, property. What some see as Sinn Féin's voodoo economics is likely to come under much greater scrutiny as a general election draws closer.
According to Henry McDonald, the recent success brings a step closer Gerry Adams' strategic plan to be in government on both sides of the border for the centenary of the Rising.
On previous form in the North, Adams will step back from ministerial office if Sinn Féin succeeds in his goal and Mary Lou McDonald will become Tánaiste.
The time for populist rhetoric will be over and her mettle will be tested as a governing politician, with all the inevitable compromises that entails.