Uncle John was rumoured to be the one who reported my grandma to the authorities. It was autumn of the 1922 Civil War, and the Irish Free State believed anti-treaty “trigger-happy harpies” were a danger to the fledgling state. My grandmother Maggie, only 14, was rounded up with other girls for passing messages to local IRA flying column members and for her membership of Cumann na mBan. Interned first in Carlow Laundry, then sent to Kilmainham Gaol, which had been refashioned as a detention prison for suspect women, Maggie was released back to the farm in Carlow that spring, but her world had changed utterly. In a small notebook, her mother recorded: “Maggie O’Toole left Tomduff 13 day October 1924 for London”, then finally, “stopt their till 3 Nov an sailed to New York in 1926 wrote by her mother Mary An Toole”.

When I landed in Dublin in May 1995 from New York – with 10 items of clothing in a vintage US army backpack, a well-worn suitcase full of history books, interview transcripts and a borrowed laptop computer – it was to a deeply conservative, homogeneous society. Divorce and abortion were illegal, while homosexuality had only been decriminalised two years previously. Mother and baby homes were still open and the tsunami of paedophile priest revelations was two months away. In these pre-Celtic Tiger days, more people were leaving Ireland than arriving on its shores.

I’d come to Ireland to research the women and girls – including my grandma – who had been held in Kilmainham Gaol between 1922 and 1923. Of the 12,000 anti-treaty prisoners at that time, an estimated 300 were women held in Dublin. Maggie was one of the youngest.