Ok, here is some critisism on what I believe can be improved.

The feeling you have about the neck finds it's origin in the pose. I can't really figure out how she is standing, but I think that the torso is turned too much to her left.
There is also the lack of perspective. I believe that you wanted a frog perspective (don't know the correct english word, but you get the idea). But this didn't work out because the size of the limbs and sword don't reflect it.
Then there is the sword, it looks as if it is light as a feather! I don't get any feeling of weight from it. And it isn't completely straiht at the handle, now it looks as if it's bending towards the viewer instead of pointing towards the viewer.

There are tons of online articles on perspective and there is only one way to learn it: choose difficult poses with lots of perspective and don't be afraid to exaggerate!

hmmm.. ^^ good draw... i think... that her head must be a little more roundness...
and the downloaded draw look a lot better than the thumb (this is normal)
honestly i like it... continue praticing soon u'll became a very good artist!.. ^^

u drew this!? wow! you've improved a lot (compared to the ones you drew when you were still a 'kid')
yes..yes..the neck..
and her head..umm make some adjustments..
she bent to the right..just a little more than what should be (i think sumimase is a little exaggerating)
about the sword..is it suppose to be pointing to the viewer?because it doesnt look like it is..
i like the shadowing though..im not good at those.
are you sure you drew this..or copied it somewhere..?