The reason for the problem Dan points out is your light is only slightly above even with the face. Look to have it about 45 degrees up with a catchlight at about 10:30. If you were working with a speedlight without a modeling light, chimp til you get the nose shadow just contacting the cheek shadow and creating an upside down right triangle ie rembrandt triangle including the eye and cheek. You could also have her tilt her head to camera right. You could help this by cloning out the bright spot and darkening the bright spot on the end of the mouth. I have seen folks bungie a small mag lite to the speedlight as a modeling light. I am guessing no modeling light because the pupils are pretty large and don't leave you with much iris to work with. I would crop to just below the hair. The arms add nothing and don't express much. I would take down the highlight on her chest as that is the brightest area in the image and it competes with the face. Might want to darken her right shoulder as it is apparently closest to the light and is pretty bright. In studio, I like to use a black net below the face to knock down shoulder and white shirts/blouses. I would clone out the plant extending into the upper r frame. Might consider kicking up the contrast on the midtones in the lit portion of the face with a levels or curves adjustment. Only so much you can do there. For b&w, a lens with great micro contrast produces more modeling through areas that would be muddy from one without as much micro contrast. Her hair highlights are pretty bright and also dominate in the image. If this was a one light shot, a sekonic meter will tell you the percentage light from the strobe with the remainder being ambient. Once you learn the percentage, ie translates as ratio, you like, you can dial in the percentage with light power or distance. I like the camera height and it has the eyes pretty wide open. Was this taken with the 85 1.8? I would want just a bit more compression, you could still use the 85 just step back and crop. I think that would be a more flattering rendering of the nose. With my ample multi busted probiscus, I prefer being shot from 15 to 20 feet. My preferred portrait lens is a 135. I have only had one person tell me they wanted their nose made bigger. Was your shooting distance about 3-4 feet? You have a nice highlight on her lower lip one facial feature I would emphasize with her. I like that you have the lips slightly parted as that adds to the fullness. Might like it just a bit more closed. Open just enoughto allow air to be exhaled. Not sure if you were going for such a blank expression, but if not, you might try keeping up a conversation with her clicking when an expression that is her materializes. Even better mention things intended to elicit a particular expression. One of the things I like about einstein lights is they can pop 10 times per second and easily 6. When an expression goes for one to a better one or gradually fades from excessive to gone, somewhere in those 6 shots can be the perfect expression. Also, I don't have to wait for the lights to recycle. On another thread last week someone commented about Peter Hurley's bonding and conversing with his subject. What he does works for him. Oh, hair on the upper right blends into the dark background, solutions could be positioning her so that is in front a a bright area of bg or adding a kicker or silver reflector from right rear. Or you could wait till the sun came up just a bit , placed it right rear for a free hair light. Once cropped, might consider a vignette or taking down the sky and the light area in the lower R. Just suggestions based on how I would have shot/edited.