very pretty girl. personally, i think she's posed wrong. her chin is quite prominent and the lower half of her face is very round and full. i think if your camera's POV were higher (above her eye level) and she dropped her head a bit, looking subtlely and slightly upwards, you'd get a better, more pleasing image of her. i'd also like to see her hair untied: pulling it back also accentuates the chin and cheek-roundness. the shot's a little flat (easily fixed in PS with levels or curves) and seems overly softened. you might want to frame tighter as so much white blouse against a white background takes away from her face.
of course, we all know the definition of an opinion... and we all got 'em...