Looking for some critique

I recently took these head shots and want to improve on them. I have a subject that is available upon request and I would love to make these better. I have trouble with posing and would appreciate any tips or suggestions you may have. I still have to do a hair editing. I also would take these during the day to get some ambient light so her pupils weren't so dilated and you could better see her blue eyes. It is very dark in my studio in the evening.

Some ideas on what I was attempting to accomplish. Subject is an aspiring author and she is looking for a good profile shot. She doesn't want the stiff poses that you see of most authors, yet she doesn't want it to be too casual. She is very shy in front of the camera and I am not a good director. Lighting wise, I am shooting her on a white background lit with flash. That way I can change it to what I want later. I tend to make it more of a gray so it is easier to make a background work. These photos were taken with a flash fired through a soft box at camera left about 45 degrees. I have another in a shoot through umbrella at camera right about 45 degrees. Both were fired about 1/4 power. The soft box is much closer to the subject than the umbrella. I didn't want that much of a difference in exposure and ratio so lights were adjusted to this. I was trying for a non smiling shoot, but the one where she kind of cracked a smile I really liked. She doesn't because she feels it makes her look like she doesn't have teeth. I took many more from this shoot, but I don't think they were what I was looking for.

Thanks again for the critiques!

Generally speaking I like the first two. I feel like the second two were taken with a shorter focal length that makes her hand look unnaturally large compared to her head (especially an issue with the last shot). I think the first one is the best.

A couple of little things I noticed were the ring and the eye direction in shots 1&2.
If the ring isn't part of the overall look or concept I would suggest removing it. it is bright and in front of her face which attracts my attention. Creates a dynamic line as my eyes move back and forth to it, but if it isn't important to the shot you might want to remove it to put more of the emphasis back on to her.
There is a lot of white showing in the eyes in the first two shots. I have learned to have subjects look at something in between their face direction and the camera to bring the iris back somewhat so it really shows up.
If you are looking for more information on posing I would suggest checking out some of the videos on the B&H website. Have seen some with Ghionis and Niekirk that cover both lighting and posing quite well. If nothing else it will help to boost your confidence and give you focus and direction in what you are doing during the shoot which will be picked up on by your subject and allow them to become more relaxed and comfortable. A lot of shyness is from people not knowing what to do in front of the camera and once they sense that you know what you are up to and have seen some shots from the shoot then it becomes a lot easier for them to open up and let you direct them.

Thank you for the suggestions and critiques.

Sean, I did have a the zoom set toward the wide end for those two. I actually made things smaller in PS before posting. I am going to try and find a little more space next time we have a shoot. Might have to move to the basement for a longer shoot.

JRW, I will definitely look into the videos on B&H. I have watched a couple videos by Niekirk and will definitely look into seeing a couple more. I hadn't thought of the ring until you mentioned it. I knew the eyes had a little too much white and will have her look at something else.

Thanks again!