She was the main author of the extensive Wynne Diaries and wife of Royal Navy officer Thomas Fremantle, a close associate of Nelson.
She was the second daughter of Richard Wynne (1744–1799) and his wife Camille (born de Royer, died 1799), who were Roman Catholics.
Elizabeth married Fremantle in 1797, after he had rescued her and her family from Leghorn (Livorno) during the 1796 French invasion of Italy and taken them to safety in Corsica.
The marriage took place in Naples on 12 January 1797, at the house of the British envoy, Sir William and Lady Hamilton, who took care of the arrangements.
The early parts, which run from 1789 to 1857 in 41 manuscript volumes, provide a vivid and informative account of a well-connected English family in Europe (mainly in Germany and Italy).
[6] The diaries, except for one notebook covering part of 1796, which was lost at sea, were preserved by the Fremantle family, but remained unpublished until the 1930s.