Thanks for the further responses. I am definitely tall (and have never smoked), but I always talk to her in a happy voice, I avoid eye contact, and generally try to make any exposure to me as positive as possible.
I just don't get her at all. I have been around dogs most of my life (at one point while I was growing up we had 6 dogs in the house!), and have never had an issue with any of them until now. Even a daft old Basset Hound we acquired - who had a great dislike for men in general - soon found a soft spot for me. We've had Pearl for over 6 months now, and there is no real sign of things changing.