I don't think there's anything wrong here. The only thing I can think of, if at all, is the lips. The somewhat small size of her lips seems to add a slightly childlike feature to her face but I can't say that without feeling like I'm nitpicking. So feel free to ignore the lip size comment.
Never saw blue hair that actually looked entirely natural. I like the blue hair and golden eye combination; its unique and you made it look natural. It's as if somewhere out there, there's actually someone who might have this hair and eye combination. She looks remarkably... Detailed? Real? Not sure which word I'm looking for, but it's a little striking, and her expression adds to it. I feel like she just asked me question and she's sitting there waiting for the answer. She's thinking "Well?" and I almost feel guilty or stupid for forgetting what the question was.
I'm not sure I catch how all of the seven sins work into this piece of art, but seeing as how one of them is indeed lust, I'm glad you didn't dive off into the graphic or inappropriate end. There is power in subtlety and I believe you caught onto that here.