[jford]

She seems a bit nervous or tense. Her arms are held nearly straight - which tenses things. She's pulled her shoulders forward a bit - which creates a sensation of isolating herself from the viewer. She's resting her upper thighs on her lower legs, which flattens both and emphasizes the size of her thighs - not usually flattering. Also her hands are not her best feature and this pose rather makes them apparent - although I can't suggest a simple fix for this pose, now that I'm thinking about it. Her hair is slightly disarrayed, which you should have caught. I personally find the slight bit of exposed skin at the back of her midrift a bit distracting and serving no real purpose.

She's quite lovely. You did really well, given a first-time model. The lighting, the exposure - all the technical stuff looks pretty good. Most subjects don't relax when you point a camera at them - it takes practice before someone becomes themselves. You should, if you can, shoot with her again a couple of times. You might consider a bit less even lighting, to increase the sculptural quality of the portrait.