I can't find the specific data on gender and age, but my impression is that there's a dearth of young authors of all genders, which I wrote about previously (link below). Although I would venture to guess that it can be harder for young men who want to be fiction writers simply because sometimes they are inclined to write fiction with only traditional masculine concerns (books that are usually described as "muscular" or contain lots of violence). They're writing for readers who aren't there. What's funny is sometimes you ask these young writers what fiction they read and it will be all the classics (Cormac, DFW, etc.) but nothing contemporary (the very thing they're frustrated about not being able to get published!).

(thanks for reading and for the typo catch)