Anyway, sorry that those thoughts above really are so random.
If you can give her a new habit that is more fun than kissing, she'll probably do it, as the best thing to get rid of an undesired habit is a new habit. Maybe give her one of those rubber bands shaped like an animal to wear on her wrist, and ask her to twist it whenever she feels like planting a big one on somebody?
With obsessive behavior if it is totally driving you cuckoo, there is nothing wrong with talking to her pediatrician or a child therapist.
Which Disney movies? :)
Some random thoughts: it sounds to me like she is being obsessive more than sexual, and for that, maybe time really is the cure, but some of the other ladies on the site might have a better answer than this. When I was little, I liked to suck on my skin of my wrist until blood came under the skin, basically, making a hickey. It wasn't from any sexual motivation, I just liked the way it felt to suck my wrist, and thought the hickey was interesting. Kids model what their parents do, I don't mean having anything sexual per se, but if you kiss her, she'll want to kiss you. My son got a big kick out of us pretend-biting his hand when he was about 1 -- you guessed it, he started *real* biting us, as a result. Didn't know the difference particularly, probably thought his real bites felt the same as the little nibbles we had been giving him.