;)
I'm guessing you call it "shading test" because you're trying out shading styles? You've got dithering on the vest, kinda fighter-y on her right arm, pillow shading on her left arm, and the there's a conflict with the light source on the pants.
Sorta unconsitant out lining too; trying selective outlining?
could almost go without the shade at "a"(EDIT: the shade above this one I mean...); would cut your color count a bunch
highlights at "b"?
missed a spot at "c"
Okay, enough with the bad, time for what's good. She's got a solid expresion and flawless muscle structure on her upper right arm. The incositancies make it fresh compared to most stuff being posted lately, but I think there's a bit too much, could be wrong though... Can't wait to see the edit.
Oh and by the way, is this going to be for a game?