It sounds to me like your kitten was feral (wild) when you got her. She most likely was born and raised outdoors by a feral mom, and has an inborn fear of humans. Patience and time should eventually win her over. Alot of us here on PT, myself included, have played the waiting game with ferals, and in time they become some of the most loving kitties we have!

GOOD LUCK, and please don't give up on her!

Kim