1. Cats like the salt content of your skin. Humans have salty skin, even if they are not sweating, there is still a good amount of salt on them.
2. She loves you! When cats groom each other that is a sign of affection and means she wants to take care of you. My cat licks me and even nibbles on my nose when I sleep while kneading (or "making biscuits", as my mom calls it) on my lap. Since she's a kitten you probably remind her of her mom.