Great work. The first thing I noticed was the softening of the skin and the enhancement of the eyes from both a color and clarity standpoint. The eyes are critical in any portrait, and this is a great example of just how critical they are. There is a more dramatic sparkle and slightly more color in the girls eye in the enhanced photograph and it makes a very big difference in my opinion.
The composition, the technical details (i.e. exposure, shutter speed, aperture settings), and color control are all spectacular in this image. I also like the desaturated look which appears more “film like” to me rather than digital. I really like the shape the trail creates in the background which adds a lot of simple visual appeal to the photograph.
The only change I would consider would be cropping the object out of the bottom left hand corner. I can’t tell what it is. It might be a bag handle or a toy but it’s unidentifiable and therefore distracting. Since you can’t include more of it in post production to show your audience what that object is, I would consider cutting it out altogether or use your “blend” or “replace” tools to erase the object and replace it with a background similar to the one you have behind the girl.
Other than that… spectacular photograph. Great job on the subtle enhancements.