Basicaly take what tkamia said and reverse it.
I like the fabric -- it really brings out the baby-smooth skin. A solid color would have been bland and detract from the skin. And I really enjoy being able to see her right hand...being out of focus, it does not lead me off the image. I like the way it also defines the distance between the child and the fence. The image is very 'kid'...drawing from having raised triplet boys. The expression (and the eyes) is what makes this an interesting portrait instead of just another snap of the kid. Kids can be very intense -- we just tend not to see it in posed photos.
Her head size may seem a little out-of-proportion, but that is realiity for you -- kids' bodies tend to grow into their head size.
Great portrait! I do not recommend any crop!