Well to begin your use of natural lighting is simply amazing. I love how the sunlight cascades through out this composition. From her parasol to her chest. I like how you just keep the shadow of the the curtain pattens on her chest instead of her face. That could easily be a distraction. Fine capture of the pastel color on the parasol. Detail is clean without any indication of noise in this photo. Good contrast of the model against the background. The models gaze is most compelling in this shot. I'm impressed by the balance of light against her face. It not too dark or too light. Even down to the sunlight dancing on her hair. I really don't see any other way to make this photo better. Maybe a soft diffused blur. But I would not add too much to this. It's fine the way it is.
I hope this critique was helpful?
Cheers.