Her face is under exposed (2 full stops) because she is back lit and it doesn't look like any fill light was used. What metering mode did you use?
The camera perspective is good. You get down to her level.
Notice how dark her eye sockets are. The eyes are the "window to the soul" and being able to see the eyses makes or breaks people shots.
Holding the camera with the long side of the image frame vertical is called the portrait orientation for a reason.
The composition being so central is weak. There is something bright, white and distracting on the left side of the frame.
Portrait poses that have the shoulders parallel or perpendicular to the image sensor plane are not as apealling as when the shoulders are at an angle somewhere in between the two.
Had her left shoulder been back a bit and both shoulders not parallel to the image sensor, you could have included the rail there camera right all the way to the curve.
In Photoshop to convert to B&W I use a B&W adjustment layer so I have more control of the contrast.
I brought the exposure up 2 stops, cropped, and dodged right above her eyes a little, and another to roughly illustrate what fill flash might have done.