A very nice picture indeed but here's some critique if you don't mind.
-Shading needs to added to the left off the ball to indicate an added light source.
-Shadow is on the wrong side with the sun(I think that's the sun)
-The arms seem a bit off because they go straight instead of curve a bit towards the middle.
-The stomach really shouldn't be curved because it looks like shes sucking it in which looks just a tad awkward.
I guess what aoisgd is saying that you give off a feel that your a young artist, which may or may not be true
But from aside that and some others you did a really nice job. Keep it up.