re background:
This bothers me the most.
I would try to get a darker/toned down background that does not distract from the subject.
Visually it is hard for the subject to compete against a bright colored background.
I think even the dark purple in the bottom left is too bright (color wise) for the subject.
I've been burned by this problem more times that I want to remember. And even with post processing, fixing after the fact can be a LOT of work. Try to fix this at the shoot.
re hands:
Someone someplace posted that one way to "minimize" the hand is to NOT shoot the flat of the hand. Instead shoot along the edge of the hand. That way the hand does not look as large as a flat on shot.
Posing the hands, has always been very hard for me, so I tend to keep them out of my pix. Yeah, the easy way out of the problem.
But like anything there are exceptions, like when a person has small hands to begin with, or a particular person where you want to emphasize the hands.
re lens:
I agree about the use of 35 being too short for that portrait. (35mm on a DX D500 = normal lens)
I would use a longer focal length for that shot.
I reserve the shorter focal lengths for full length or group shots where I cannot back up any further, like when my back is literally up against the wall of the room.
re camera position:
It seems to me that the camera is down about her chest level.
That would emphasize her hands, because her hand is closer to the camera than her face.
I would get higher, maybe up at chin or eye level, to increase the distance to her hand.
re hat:
I think a hat can be an important part of a portrait, so don't think you have to get rid of it.
It is a challenge, but hey, we want the subject to look good and happy. In fact I rather like the pix with her hat.
However, if the color of the hat distracts from her face, that is another problem.
No, not the bright orange hat!!! argh
I would lower the softbox, to get more light under the hat. Yes you are changing the light plan, but to me that is better than the shadow of the brim.
Gud Luk