Welcome to GG! I'm sure you'll love it here.
As to your images, I don't like the first one personally. Her left arm looks like it's been broken and bent the wrong way and the leaf in the upper corner is distracting. That's minor though. Photoshop is a wonderful thing for those little distractions. [img]/ubbthreads/images/graemlins/wink.gif[/img] I think Mike mentioned her smile looking forced and I'm kind of seeing the same thing. Sometimes the difference between capturing the natural smile and the forced smile is a split second because the face is transitioning as a person smiles and if the shutter release is pressed just a microsecond to quickly, it can capture the "forced" portion of the smile.
The second image, in my humblest of opinions, is a much stronger shot. Her smile looks more relaxed (and she has a pretty smile) and the positioning of her head makes it a stronger image too. There appears to be more confidence in her posture. Her hands being cut off is an issue but maybe your original has her hands shown.
Just some thoughts. Thanks for sharing and have a wonderful weekend!!!