I really like those glasses frames! In a head shot, where you can't see much in the way of fashion, and don't want to overwhelm with facial/ neck accessories, unique glasses frames can lead a viewer to linger a little longer on a photo. Not to mention, these frames do a great job of framing her eyes. However, there is the issue of glass glare. In the shade, facing away from the sun and reflective surfaces there wasn't too much, but I used photoshop to sample her skin and eye tones and painted over the glare, building layers using low-opacity digital paint.
I didn't know this until I googled it today, but the industry standard size for headshots is 8"x10". Some cropping required. When cropping (or composing photos), don't be afraid to cut off the top of people's heads; the most boring part of the (front view of the) head. Viewer's minds will automatically fill in the arc of the crown, anyways. Often, it's more visually compelling to get closer to the face than to include all the head or hair.
Way back when, while event photographing, I cut off the top of a guy's head. He looked at the digital image at the back of my camera and protested. Why is the top of my head cut off?! Personally, I think he had issues because he was particularly tall. But rather than to explain the aesthetic virtues of my compositional style, I just took another pic, including all of his scalp. He was happy.