It's not horrible, but it's not quite okay with me either. I would not want to be named
Evan. I know guys named
Evan.
Evan Rachel Wood probably did make it seem more usable for girls, but ... her image relates really well somehow, to my overall sense of aversion to using such a name for a woman. Not that I disrespect her, but. The style (masculine personal names for females) is very Hollywoody-seeming. Maybe because people with such names are only noticeable when they're entertainers, and female entertainers are invariably presented as specially cute and young - but whatever, it comes off as sort of sexed-up to me.
Still and all, the name
Evan does take on a much lighter feeling than, say,
Ryan or
Adrian can, when I imagine it on a girl ... it almost seems like a different name from Evan-on-a-boy. So I have to say it does work, and it doesn't even really contaminate the name
Evan for boys. IMO. Unless people start using it as much for girls, anyway. I think it could become unisex sort of like
Dana (which, btw, I noticed is the name of
Evan RW's brother!).