Here's what she isn't: an ambassador, a politician or a head of state. Here's what she is: influential, articulate and possessed of a conspicuous platform as a former President.
Clearly, Mary McAleese is intent on using that portable podium to advocate on behalf of causes she holds dear. In recent times, she has been busy carving out an imaginative space in relatively uncharted waters as an envoy without portfolio.
When she speaks in public, she chooses her subjects so deftly that her interventions have the authority of giving voice to the Irish people. She managed it last week in the wake of a 'New York Times' article, which made callous inferences about Irish students on J1 work visas following a balcony collapse in Berkeley, California.
She did it again during the same-sex marriage debate. And she has been a persistent thorn in the Catholic hierarchy's side, questioning its stance on the male hegemony.
Being answerable to no one, Ms McAleese is all the more powerful. Now that she is no longer President, her ability to contribute to national debate is exceptional.
That's not surprising. After all, she spent 14 years as First Citizen and inevitably the position confers gravitas. That quality doesn't disintegrate as soon as a presidential term or two expires.
But she was constrained in what she could say by the formality of the presidency. Today, she is in a position to speak more forthrightly than was possible when she called Áras an Uachtaráin home.
Her natural inclinations, along with the freedom of no longer being a public officeholder, mean the gloves are off when she sails into battle. So it was that she pulled no punches when she reproached 'The New York Times' for racial stereotyping of the young Irish people killed and injured in California. Others echoed her expression of injustice, but it was Ms McAleese's rebuke in a letter to the editor which struck exactly the right note. Her intervention captured the national imagination.
As President, she could not have engaged in a newsprint war of words, but no such fetters bind a previous incumbent. Her measured remarks helped to offset that communal wince experienced by many Irish people last week. A public service was performed by the lady on that occasion.
It's the latest in a series of high- profile interventions. Many found her comments during the same-sex marriage debate persuasive, when she said passing the referendum would help to dismantle the "architecture of homophobia". Even those unconvinced by her argument could not dismiss her courage and conviction.
And her comments in Sligo last month during Prince Charles's visit struck a chord: "We all know what the past was like, it was not a pretty landscape. I think today something much more gracious and beautiful is let loose in the Irish air." Such words remind us we have the capacity to change for the better.
On the subject of change, she is determined to challenge the upper echelons of the Catholic Church. No pussyfooting about with diplomatic language, either. For example, she described as "bonkers" the Pope's plan to ask a synod of bishops to advise him on family life teachings. What did they know about it, she demanded?
The former First Citizen's views can be a lightning rod for controversy, and not all citizens will feel she speaks on their behalf. Some may be uncomfortable with this new model of vocal ex-President, and may prefer the previous pattern of secluded retirement.
But what contribution to national life does silence make? Where is the public service element? Besides, that mould was broken by her predecessor, Mary Robinson, who resigned to take on a prominent role as a human rights activist with the United Nations, and has gone on to be a climate change campaigner.
A common denominator is that both were relatively young and active, still in their forties, when elected.
Ms McAleese was only 60 when her two terms expired in 2011, compared with Éamon de Valera vacating the Phoenix Park at the age of 90 in 1973. Coincidentally, Ms McAleese celebrates her 64th birthday on Monday, bringing to mind the Beatles' question about being needed at that age.
Having humanised the presidency without diminishing its stature, she is now preoccupied with reinventing the role of erstwhile President. And she's doing it while pursuing other interests, such as studying canon law in Rome.
All things considered, I say we do need her, even if we disagree with her from time to time. Do we have such an excess of intelligent, eloquent people in public life that we can afford to tell her to rest on her laurels and keep her insights to herself?
Her missteps were few in public office, and she was as discreet as the role demanded. Now, she has the freedom to speak boldly. What's the point in belonging to an exclusive club - the Guild of Retired Presidents - if you keep your star wattage in a drawer? There are enough retired people on the golf course already, and memoir writing is only useful if it serves up the unvarnished truth.
Her interventions remind us that there is quite a lot a President can't do, but fewer limits on a former President.
No wonder the question hovers: what will Mary do next?