My precious Ophelia (who's now crossed the Rainbow Bridge), a beautiful semi-longhaired calico, did this sort of thing, too. I would awaken to find her trying to nurse my neck (of all placed) while kneading and purring up a storm. Her mother became seriously ill immediately following the birth of Ophelia and her littermates, so all of the kittens had to be hand-raised. The vet thinks that her later behavior was due to her having been bottle-fed.
Despite the "nursing," I miss Ophelia fiercely. Rest in peace, sweet, sweet kitty--I love you.