I have an embarrassing confession to make. Unless the information has been handed to me in an author bio, I am often remarkably clueless about the personal details of the people I read. Age, gender, race, religion, orientation, ethnicity-- I know they matter in shaping the person who's shaped the story I'm reading, but finding these things out isn't high in my priorities. I read speculative fiction because I'm interested in the world inside the author's head, not their place in the world outside of it.
Sometimes the answers are obvious, of course, either from the author's name (if it is the author's real name) or from the context of the stories he or she writes. If I see initials instead of a first name, I'll suppose the author is female-- men don't really need to hide their gender to sell books (except in the Romance genre). In the absence of other clues, I'll generally assume the author is something like the book's main character, if I take time to think about the matter at all.