This piece captures the character well; it has a very pronounced and rough look. The background make it look a bit unfocused, as if she isn't really pointing at someone, but just making a quick pose.
Props on the lines used in the hair especially. The amount of detail in the top versus the bottom seems unbalanced. Maybe if you added the other hand into the picture you could produce more expression.
Lastly, the face seems odd, a little alien. I suggest using some white in the eyes, or adding more natural lines to give the face expression.