I have been wondering about this question for a while now...
In JinYong novels, it seems, there are no top-tier female fighters (or, at least, not that many) (although there's always A Qing although this, too, is debatable).
In the "Godly" level there's DaMo, Sweeper Monk.
In the "Slightly less than Godly but still a total pwn" level there's XiaoFeng, DuanYu, XuZhu, Xiao YuanShan, MuRong Bo, etc... (of course there's TSTL and LQS of HDSD, but they're only two among many, many male fighters) (I just love parentheses, don't you? )
So why do we see such a gap between genders?
Of course it makes sense that in the lower levels (think: really low levels, like JiangNan7Freaks) it makes sense that guys are stronger; with no internal energy factor, guys will win: they're just naturally stronger.
But why is there such a gap higher up, when physical power is no longer important (relative to internal power)?
Is there any barrier that keeps women from developing awesome internal powers? Because it is the only explanation that I can think of, however nonsensical.
Or is this just a "Guys Must Win" attitude from our favorite wuxia authors?