Perhaps a tighter crop (left and bottom) may have made this a stronger image. Good focus and nice expression. The pose is nice but I just noticed she has her fingers on the chords, yet the other hand is not playing, so perhaps relaxing that hand - but minor and, may have ended up too 'directed'.
Needs more colour balancing... I'm not sure the white balance was good here. Lots of empty negative space to the left, not a very convincing composition. Why form a chord with the left hand if the right hand is posing for the camera? A bit of a mixed message there. Nice model, you've not flattered her ankle and you should generally aim not to see the bottom of the feet in a portrait. Have you come across rule of thirds? That will help you. Nice shallow dof, good bokeh.
A good pose and camera angle. The background is too busy, though and the positioning in the frame is too centred. I think a closer crop would help. I can imagine the guitar almost filling the frame.