She can't date a boy who is not a JW. If she does she's going against what she's been told. She can only date a JW boy if 1) they are old enough to marry 2) marriage is their intention. They can't hold hands, cuddle or kiss unless marriage is on the cards. Sex is a total no no until the wedding night.
She is trying to be a 'good girl' and to do what she's been told, whether she's interested in you or not. Being human she is probably in a dilemma. Her 'kiss me' to you is indication of her real self coming out which she then quickly squashes because now she is being a 'bad girl' and being disobedient.
You have to ask yourself if it's worth putting yourself through all this. Is this what you want from a girlfiend?