I think the color here is very soft a pretty. The composition would be stronger if there was a tighter crop around the face. I think as it, it looks too much like her chin is cut off.
Good job matching the eyes to the background. Also the lighting is nice. The depth of field is a little too shallow, so her right eye is a bit too soft. (Raise the aperture number) If you shot more of a profile shot, the softness would not matter as much, but as it is sort of in the center, it attracts a lot if attention. I'm not sure I agree with cropping her chin off. I also think that you are shooting down on her too much. Perhaps you could shoot more on her level. This would also get rid of the large shoulder element on the left side. One last thing, make sure you set the size to 640X640. You are not using the full image size available to you. Overall, nice tonal pallet.
this came in at 450x420 (which is close enough for me to a square) but could have been better as 640x640ish. The crop at the lips spoils the shot as well. She has gorgeous eyes and face and I think you could have made more of that
I am not sure about the square crop on this picture ? I think personally I would have liked to see more of the lower part of the girls face and perhaps less of the top head ...