Less than six weeks ago, the Democratic Unionist leader looked untouchable at the head of Northern Ireland’s power-sharing administration.
She took over from retiring Peter Robinson early last year in a seamless transition, and defied the pundits to repeat the DUP’s best ever election result in May’s Assembly poll.
The 46-year-old former solicitor, who survived two horrific childhood experiences of IRA violence, carried vast moral authority among unionist voters to govern alongside Sinn Féin.
She and erstwhile foe Martin McGuinness pledged a new start for Stormont and in the months following the election a non-aggression pact in which they declined to criticise each other looked to have put the institutions on their most stable footing for years. However an intense furore around her handling of a botched eco-energy scheme, that has left the executive facing a €565m tab, has blown that asunder. She may well return to her job on the other side of an election, but it is an election that she was not anticipating for another four years.
Ms Foster grew up near the border during the darkest days of the Troubles.
Born Arlene Kelly in 1970 near the village of Rosslea in rural Co Fermanagh, the early part of her childhood was described as idyllic.
However, by the age of eight she gained first-hand experience of the Troubles when the IRA tried to murder her father, a farmer and reserve police officer. She has spoken of the trauma of seeing him come crawling into their isolated farmhouse with blood streaming down his face after being shot in the head.
He survived but the family had to flee their home and the Ms Foster had to change school. As a teenager in 1988, Mrs Foster survived another republican attack when the IRA targeted the part-time Ulster Defence Regiment soldier who was driving her school bus. The Collegiate Grammar School student escaped relatively unscathed but a friend sitting close by suffered serious injuries.
A solicitor by profession, Ms Foster still lives in Fermanagh with her husband and three children. Her political career began while studying law at Queen’s University in Belfast where she joined the Unionist Association — part of the Ulster Unionist Party (UUP).
The pair had been part of a tight-knit group dubbed the “baby barristers” who opposed the Good Friday Agreement