Your art is cool, Marin! You do nice eyes and even nicer shading, they feel nice to look at ^_^
Adding to what Roji said, if you don't mind:
though the size of the head makes the other body parts look a bit strange , enlarging the torso width (as well as the arm width) would make it look a lot better. Makes her look more physically fit, in my opinion. Then again, you can never be too versatile with anime-ish art, so you might get greater reception just improving the style the way it is instead of just accounting for what was pointed out in the current criticism and improving it from there.
A little more advice, though you may already know this:
Drawing people and objects in different perspectives one after another would probably improve your skill more than just drawing the same subject in the same perspective over and over. That way of thinking very much hindered my own progress, so I hope anyone reading this gets something helpful out of this advice.
I'm looking forward to any future pieces!