Nicely done! It's very well simplified, though keep an eye out for more straight and simple C lines as you progress further, it can help avoid overcomplicating some S curves down the line.

Something that helps with proportions is comparing what aligns vertically/horizontally with a selected point on the image, like for example, the edge of the nose on the right aligns vertically with the inner corner of the eye on the right in the portrait photograph. Checking alignments like these help keep proportions more closely tied to the original, though this course will cover the lesson more in depth later on. Another tip is to draw the outlines for the values very lightly, so that the values themselves can define the shape edges and cover up the light lines. That way, without the harsher outlines visible, the drawing will have more three-dimensionality and you will be able to assess the value read better. Keep up the good work, I hope this helps!