C&C per req:
1. Nice lighting here, but I think a reflector to bring a little catchlight into her eye would have made it even better. Railroad tracks make great (albeit cliche'd) leading lines, however in this case, they do too good a job, and take the viewer's eye right past the subject and to the back of the image.
2. A little loss of detail in the shirt, BUT nice catchlights and a great smile. A little more subject-to-background separation would not have gone amiss.
Overall, nice, solid shots.
Just my $00.02 worth - your mileage may vary.
~John