This is just a quick practice exercise. Portraits are fascinating because you need not only to capture a likeness but more importantly the spirit of the person. The subtle turned up corners of her mouth indicating the beginning of a smile, the twinkle in her eyes, the impishness of her demeanor are all difficult to capture. But, these are the small elements that bring life to a portrait. Practice is what makes it possible to concentrate on these subtleties. Once you are no longer so concerned with proportion and facial structure you can begin to work with line to describe a bit more of the spirit. So, I keep practicing.