Those are the first sketches I did. They are about 3 minute long quick sketches I did just to see how charcoal works as a material.
Here I focused more on shading and how it gives volume to the figure. I also tried experimenting with all the different ways of using charcoal in order to achieve a variety of different lines.
This is a 40 minutes drawing. I am very satisfied with the way it came out. I like how I managed to define various body structures such as the skin on her back or her elbow bone.