I'd like to give this piece special mention because it *doesn't* resemble Lena Headey all that much (at least not to me). And believe me, that's not a criticism. I don't believe Lena is all that suited to the role. This, however, looks a lot closer to the true Cersei Lannister.
The character I love to hate and grudginly love as well. I like that here she seems somewhat surprised or defeated, she deserves it. Quite beautiful though, and you've clearly portrayed that part of her.