Keira Knightley WIP

I started drawing 2 and half months ago and I wanted to know how realistic I could draw at this point, so I started this drawing of keira Knightley. I am trying to draw as realistic as possible with my current techinique and drawing knowledge.

size: A4
materials: mechanical pen 0,3 mm (hb,b, h2), eraser, tortillons
total time (including sketch): 20 hours

reference picture:
[link]

finished it today (april 29th 2013):
[link]