Excuse me for asking:
Who cares what age the author is? Is the book good is the question.
Readers certainly don't care. To bring up a well-used example, Louis de Bernières didn't sell a million copies of
Captain Corelli's Mandolin because of his youthful good looks.
I suspect this is less of an issue with genre fiction than with general fiction, but there certainly has been much discussion in said circles about this. If you are under thirty and good-looking (especially if female - males can get away with being "Interesting") then it gives the publisher something to promote as you don't necessarily have a built-in genre readership. But in the end, the books still has to be good, and that's where word of mouth comes in.
I can't remember his name (probably just as well), but I remember one author (male) who was included in one of those "hot young writer" features - for which read he was in his 20s and the dead spit of Hugh Grant, and he had a novel coming out. I didn't read that particular novel, so it might have been good, bad or indifferent, but it still sank without trace. Sad to say, when that happens it's probably goodbye to that novelist's career, at least under that name.
I'm 46 next month, and I'm currently writing YA novels. I do feel encouraged that at least three children's/YA novelists I greatly admire (David Almond, Meg Rosoff and the late Siobhan Dowd) were older than I am now when their first MG/YA novels were published. I can only aspire to be as good as them.
