As the television series Who Do You Think You Are? is testament, you never quite know what might emerge when you start digging into the family tree.

Wander through Rookwood cemetery and there's a small grave tucked away near the Russian Memorial. The grave is that of Brigid Mary Partridge, also known as Sister Liguori. It is tidy but nobody appears to have left any flowers recently. That might be about to change. First came the book The Extraordinary Case of Sister Liguori and now a screenplay is in production and negotiations for a movie.

Sister Ligouri.

At the age of 18, Brigid decided to enter an enclosed convent near her home in Kildare, Ireland. Within weeks it was decided that being close to and seeing her family might 'harm her vocation'. She was put on a ship to Australia where she knew nobody and entered the Mount Erin convent in Wagga Wagga. It was from there that Sister Liguori caused quite a stir.

One foggy winter night in 1920, barefoot and wearing just her nightgown, she climbed out of the Catholic convent window.