Exposure seems good on all of them (snow is white as it should be). In the first pic you could have been at ISO 100/200 and f2 (to put more emphasis on the subject) and still have decent shutter speed. Maybe a fill flash would help make her face a little brighter.
Thanks for the comments. I'll certainly take them on board next time. That first one was on fully auto (forgot to change it back after my wife had taken a couple). I did find a few of the pictures seemed slightly underexposed and white balance was a bit off so adjusted in Aperture.
NEX 5N, SEL16f28, SEL1855, SEL55210, FDA-EV1S