Icons lie! Or something...
Just a heads up for everyone,
kitty_phase (X-Men: Evolution) and kitty_has_claws (X-Men: Age of Apocalypse) are the same person from alternate realities. Obviously, the way they are depicted is not super similar looking:
However, that's really just artistic styling differences. (Even in just my Kitty's icons you can see how different she looks from artist to artist.) As far as your characters are concerned it's okay and good to recognize the resemblance. But there are some differences, so it's okay not to get it right away too. ^^
They are physically different in that: My Kitty is lalala...maybe 5-10 years older (shhh, comic books don't like to give ages), she's had a rough life so there are probably some little scars and such, her body is more muscular and developed, and her hair is shorter and lightened. (Yeah, I don't get the lightened thing. So the world is in shambles and that's the reality where hair dye is a must? pfff...)
And then just a world of personality differences. So the way they carry themselves and the expressions they use are probably different too.