This is very nice, great expression and pose, a little light to seperate her hair from the background would have been nice, but the image has a lovely happy mood.
I think you should try a dark frame with this photo. As it is, the spot where the pullover just touches the left edge of the picture is a bit distracting (especially with the white framing provided by Usefilm). I've tried running a 5-pixel black stroke around the photo, and I believe it does help somewhat.
The lighting is great, and Silvia's smile really makes me enjoy looking at this portrait. It just radiates good emotions.