[cypher]

It could have been because you had a different scent on your hands or it could be that she wasn't too happy about your hand in the cage, it's not always easy to tell why when something like this happens.
Usually keeping your hand by the door is fine but some really don't like hands in the cage (in their territory) & it's better to interact out of the cage in a playpen/bath or other safe play area.
Try not to feel too nervous, I know that may sound easier said than done but f she hasn't bitten you before that she's unlikely to do it again.