I think the light on the second one should be towards her face more. If you notice, the face is darker than the chest, unless you were going for that. There's also a distracting thing to her left, which could easily be removed with photoshop.
I like the second one the best. It seems to convey the mood that you were trying to go for. After that it's the first one, although i'm ambivalent about the flat lighting - it makes the face, but it also is detrimental as it empties it of character.
Edit : come to think of it, i really like the third one too. It's a great moment, and except for the cut-off elbow, everything is perfect almost - the face, the smile, the hand holding the hat, the lighting. I wish it were a bit more in focus. Not even completely and immaculately in focus. Just a bit more.