1) This article woefully Needs More Examples (and maybe more wicks; it's only barely above 150 at the moment). I don't think this character type is that rare.
2) Is it possible to have a male version of the trope? Perhaps if it's a particularly "feminine" (or at least not really "masculine") boy?
Mystik
10:11:14 AM Jan 22nd 2012
I'm not sure I understand why it's a gender-based trope. It seems to really just be about the "in-between" area for superpowers. Maybe it's most frequently female, but certainly not to the point of being Always Female, surely?