Fanny Adams

From Fanny Adams (1859–1867), a young girl brutally murdered and dismembered. Tins of mutton introduced in the British navy after her death were not liked by the sailors and were humorously said to be her butchered remains. Fanny Adams then came to mean any worthless thing, and, eventually, nothing at all ("sweet F A").

Coincidentally, the initials "FA" also fit the vulgar term fuck all, also meaning "nothing at all", leading to later perception of "Fanny Adams", or "FA", being a euphemism for the latter.