Feminine as Kaworu was, I don't recall him actually having boobs. Also the shape of the bangs, and the main three eva pilots. So Rei, unless you have something like an artist's note that says otherwise.
Rei's hair doesn't flare out like that, her hair is not that color, only in the finale did she ever show even the capability for that sort of enthusiasm, and they're both connected to Adam.
How anyone could see that and right-off think "Rei" is beyond me.