"The word pussie is now used of a woman" [Philip Stubbes, "The Anatomie of Abuses," 1583]But the use of pussy as a term of endearment argues against the vaginal sense being generally known before late 19c., e.g.:
" 'What do you think, pussy?' said her father to Eva." [Harriet Beecher Stowe, "Uncle Tom's Cabin," 1852]Pussy-whipped first attested 1956.