I wouldn't be worried in your shoes, she isn't trying to hurt you, maybe just enjoying getting a reaction or trying to play with you. Or testing how it feels or sounds when she hits something with her hand. Still you might want to discourage the behavior since as she gets bigger she could hurt someone.
Re-directing her is a good idea. You could try telling her "soft" while rubbing her hand gently on your face. And then praising her and smiling when she gives soft touches "good job soft" That is what helped with my kiddo anyway when she was younger.
Another thing that helped me when my my little one was biting, was putting her in mini time-outs. It would happen when I was holding her or nursing her. Whenever she bit I would put her down on the floor and avoid eye contact for several seconds or half a minute. She hated the loss of mommy's attention, and after a few days she was no longer biting for the most part.