I'm not real crazy about the 2nd pose, and the model could warm up her smile a bit. The background is rather extreme for a general purpose portrait. So, unless you had a specific reason for doing jet black, I would suggest that some harmonious color is more fitting.
The remaining comments relate primarily to the first pose.
I am having some difficulty in figuring out what the lighting source and location are, but from the catch light, the predominant light is clearly to the right of the camera - possibly an off camera flash, off-axis to the the right. The lighting is much too flat and gives little feeling of depth to the facial contours.
That could be improved upon by raising the light much higher and swinging it further to the right. If a second light is available as fill, use it to soften the shadows from the modeling light.
I do see some evidence of another light to the left, but I am not seeing its catch light. Perhaps someone got clever and removed that second catchlight in Photoshop.
In any case the lighting is too flat, but it is a very nice portrait with good exposure, good color balance and the only harshness in the lighting is the hot spot on her left cheek, indicating that more diffusion is needed.