"The Wordsworth Book of Euphemisms" by Judith S. Neaman and
Carole G. Silver (Wordsworth Editions Ltd., Hertfordshire) under
the entry for
"Male identified or Oriented. Homosexual (male) says:
".A Molly (1750).
A lavender boy and a Nancy, Miss Nancy, Nance or Nancy Boy.
The name Nancy has given rise to the British rhyming slang
expression 'a tickle your fancy' (after World War II)."