She does appear: she’s the last icon in the bottom row on the right on your Campers page (hover over the link and you’ll see that it links to http://this.thatcamp.org/profile/sharonwebb/. She would need to enter her name and/or a photo in her profile to make it clear that it’s she.
She can’t register because she’s already a user: the main point of registration is to create the person a user account on the site. If it bothers you to have the registration list and the user list out of sync, you could remove her as a user and let her fill out the registration form.
Admittedly, the registration form should probably give you an error message along the lines of “You are already a user on this site” when you submit a registration request and are already a user, which I’ve just tested and which apparently it doesn’t do. We don’t have any developers currently who might add such a message, but maybe this weekend I can take a look to see if I can add it in myself. It’s probably beyond my capacity, anche se. Spiacente!