First of all, I find your exposures to be good. I don't see mention of any off camera equipment in your sig, but your exif data says no flash was fired. I'm not really sure if you used fill or not, and that's a good thing. 
I find the pose in #1 to be a little odd although the shot is sharp. The second shot is a nice goofy candid. #3 is a much better pose, but I'm not crazy about the gadget or at least how she's holding it. #3 also seems a little soft. A kicker light might have helped a little.
As for the first and third photos, my advice would be to crop them
I'm a big fan of filling the frame also. I like to take a couple of different focal length shots of the same scene then pick my favorite later. #3 especially could have been a little tighter.
Looks like you are on the right track. These shots really are pretty good. My critique sounds a little nitpicky, but I'm just looking for places you can improve.