Wow! That picture looks great! Love the angle.
Aww, that's so sweet.
Tips for shading? I am self-taught so I can only tip from experience, i.e.: there may be an easier or more efficent method than the one I am presenting.
The farther the object is from the light, the darker it would become. That is why there are shading tables for reference like this one:
This also applies with depth. If you have a skirt with a deep pleat in it, the deeper the pleat, the darker it gets. So when I am shading, I have to keep in mind what kind of shapes and textures are in the picture, and the placement of objects so when I shade it doesn't look as though they are 2D. Unless you have a hard light, shading should be soft, and hardly perceptible unless you put your finger in the middle of it to block most of the transitioning.
I really think your shading is excellent, and well-placed! I say it doesn't need any adjusting; it looks great.