I rather like #2 and #4, #2 seems a little confused in subject but exposure and sharpness are fine
#1 is a bit over exposed but nothing little time PPing in PS wont fix
The "Laura" shot : Im sure fill in flash would have got rid of the shadow
Tobers has mentioned a wider aperture to get some useful Background Blur
A nice set all in all.

. much in keeping with the ones on your flickr site