A good start - it always helps to have an attractive model to work with. C&C per req:
There's nothing seriously wrong with this image, but there are a few niggles: (1) You're cropped too close to image right; always try to avoid cutting limbs along their axis or at joints. As a general rule, compose your shot exactly the way you want, and then zoom out a hair. (2) In portraiture, you should usually try and have the subject's head and eye's looking in the same direction. It's fine to have their head turned, but not so much to have them looking off to the side and (3) Very minor, just a bit too much shadow on the left side of her face. A reflector would have really helped here.
Just my $00.02 worth - your mileage may vary.
~John