I think her hands are too close to the bottom edge of the frame,creating tension at the lower edge of the frame. Also, her shoulders are perfectly squared up to the camera-subject axis, making her look big and broad-shouldered. it really isn't a head shot either--it's a half-body shot.
A more feminine and engaging pose would have had her shoulders at a roughly 45 degree angle to the camera, show that we can see she has a bustline. The bottom of the frame would then be made up of her body going all the way across the bottom edge of the frame, creating what is called a "base" for the portrait. This would slim her down in appearance, show her bustline and attractive figure, and would eliminate the distracting hands at the bottom of the frame.
By angling her body to the camera, she would appear more dynamic, and eliminating the squared-up shoulders would make her look much more fit and less masculine.