I like what you're doing here...but I'm not sold on the lighting pattern/direction you have on the model. It doesn't fit with the ambient/sun light, (which in itself is OK), but it's just seems too much in this case. The light on the model is high and right in front of her, almost mimicking sunlight (but we know that the sun is behind her). Plus, it's so high, we don't get any light in her eyes.
I think this lighting pattern could still work, if it wasn't so high contrast...maybe if it had some fill etc.
I wonder if it would have worked better with side lighting...maybe dramatic side lighting from both sides.