Published reports differ regarding the actual date of Eliza's birth. For many years, it was accepted that she was born in the city of Limerick, as she herself claimed, possibly on 23 June 1818; this is the year that was graven on her headstone. However, when her baptismal certificate came to light in the late 1990s, it was established that Eliza Rosanna Gilbert was actually born in Grange, County Sligo, in Connacht, Ireland, on 17 February 1821. At the time of her birth, all of Ireland was part of the United Kingdom of Great Britain and Ireland. She was baptised at St. Peter's Church in Liverpool, England, on 16 February 1823, while her family was "en route" to her father's post in India.