Michelle O'Neill admits she does not get enough sleep.
"Sometimes I find it hard to switch off, so sleep is not always great," she has said.
But if the 40-year-old Country Tyrone woman, whose birthday was just last week, has a mantra, it is her father's advice that "life is for living".
The Health Minister appears to be the frontrunner to replace Martin McGuinness as the leader of Sinn Fein in Northern Ireland.
While other names are in the frame, O'Neill has been increasingly pushed forward over recent weeks - and not just in terms of facing the media.
It was she who in the Assembly last Monday announced her party would not be re-nominating Martin McGuinness for Deputy First Minister.
"If we are to return to this chamber," she said, "there must be real, meaningful change. There must be respect and equality for all sections of society."
O'Neill, a mother of two children called Ryan and Saoirse, has been involved in the Republican movement since she her teenage years and is a qualified adviser in welfare rights.
She has a reputation as a hard worker and seems, even under pressure, to remain even-tempered despite her staccato-style speech - she is said to be the fastest speaker in the Assembly.
Her rise through the party has been steady rather than dramatic. She worked for eight years as a personal assistant and adviser to MP Francie Molloy, for whom his colleague's biggest strength is her firm grounding in local politics. In all their time working together, they never fell out.
"She is very level-headed," Molloy said. "I never saw her breaking off contact with people. Instead, she would be trying to find a resolution.
"She is a very personable person, very friendly and easy to work with, which I would not say about myself. "
O'Neill has a fairly rigorous personal regime, rising at 6am daily and often heading to the gym for a 'pump' class.
At school she was not a great fan of PE - "I tried to get out of it many times," she has confessed - but has tried to find time for diet classes in recent years.
But she also admits to a few guilty pleasures and enjoys a tipple now and again.
Despite Stormont's often long hours, she likes to be around to cook an evening meal, even if only to avoid husband Paddy's knack of feeding the children waffles and spaghetti.
After eight years in the party backrooms, she was elected to the former Dungannon and South Tyrone Borough Council in 2005, representing the Torrent electoral area, and five years later became the first woman to serve as mayor of the borough.
In 2007, she became an MLA for Mid Ulster, after which she gained a place on Stormont's education committee and was nominated as her party's health spokesperson - solid training for becoming Health Minister.
First, however, in 2011, she was appointed Minister for Agriculture and Rural Development (Dard). While appearing not to achieve the popularity of her predecessor, party colleague Michelle Gildernew, O'Neill had a good relationship with farmers.
Even yesterday, only a few hours after McGuinness stood down and with an election to fight, she was in the Strabane area visiting beef and dairy farmer Derick Donnell and dairyman Ernie Colhoun on their farms.
She earned more praise than brickbats for her rural development programme and allowed farmers quicker access to their single farm payments.
She also oversaw the first moves towards decentralising her department, with the relocation of the Dard headquarters to Ballykelly in County Derry, and the moving of the Rivers Agency headquarters to Cookstown, creating 80 jobs.
As Health Minister, she was about to step up plans to tackle waiting lists when the RHI scandal erupted.
Should she be confirmed as Sinn Fein's next northern leader next week - and until recently the received wisdom was that Conor Murphy would get the nod, although Finance Minister Mairtin O Muilleoir was also tipped - it will mark a clear break with the past.
There are few doubts that Sinn Fein president Gerry Adams remains in control of the party, his grip appearing to tighten further as Mr McGuinness made the decision to not seek re-election over his health issues.
The appointment of O'Neill would also fit into the "inspirational" tone McGuinness has talked about, signalling another shift away from what was seen as an IRA army council ascendancy.
However, commentators are, as ever divided.
Alex Kane said: "She will not spook unionist voters in the way that Martin McGuinness used to, or Conor Murphy might do. That would make her a very canny choice to replace McGuinness.
"The fact that she has no IRA baggage is also the clearest possible signal that Sinn Fein can send that they remain wedded to the democratic process.
"Just as important is that it would be a signal that the IRA army council, which we know still exists, is 100% wedded to the peace process."
But Malachi O'Doherty argued: "If she is appointed, we have no disclosure of the process by which she has been chosen. That would suggest that she is the anointed of the old guard and raises the fear that she will be their puppet in office rather than a creative new energy in her own right.
"If Michelle really is just appointed by Adams rather than elected by the Assembly party, she is as much a product of the dark past as anyone else."