Very nice; C&C per request:
1. Very nice capture, lovely expression. I would suggest darkening just a hair as it seems a little too bright. The background is a little distracting. A reduced DoF or perhaps some artistic blurring in PP would improve this.
2. Very nice; good lighting and composition, however again, be cognizant of your backgrounds (I know this is very difficult in this sort of enviroment). As per comment for #1, reduced DoF or blurring would help isolate the main subjects.
3. A nice, candid portrait, but again, a little too bright in the face/shirt. A quick tweak of levels/brightness would fix this up.