Whedon's characters are always sort of asexual to me, I mean in the sense of being not particularly coded for either gender (except in clunky I waaaannnnnaaaa have a booooyfriend and great hair! ways that I ignore anyway).

I've yet to find a female character I totally can identify with--as I've ranted extensively before, the women who have exciting lives (Buffy, Joan of Arcadia, Jaye of Wonderfalls, etc) generally resist them for ill-defined reasons, probably because the mostly male writers can't think of a real reason for dramatic tension. *grump*

Now Ace in her 20s...mayhap.