This is quite a good image. The purple and the green sit nicely with the skin tones and tree bark. The composition is good, but the shot is really about her eyes, so I feel the image needs to be more focussed. The flowers and her hands are distracting from her face. You could easily crop the shot in closer, and maybe darken her hands in photoshop. I would also lighten and sharpen her eyes a little. I would also title it "Her eyes" rather than her smile, because you can't really see her smile. The lighting is good, and nice use of the reflector with the catchlights in her eyes.
I thought I recognised a certain style in your photo, and then I saw you had the workshop with Librodo. That must have been awesome!
Great colors! Not much critique here, except the dark area above the models head. It's kinda distracting and it seems like something is growing out of her head. Change POV and the problem's gone ;)
Very pretty lady, however the eyes seem soft. Try using layers to soften the sky and sharpen the eyes. That will make her eyes pop out. And to me in a portrait the eyes are the most important feature.