I picked this image as the best from the group of photos. To me, this image displays a lot of emotion and security.
The crop of this image is really nice. Some of the other photos were not as tightly cropped which allowed for some things that were around the kids, become distracting.
The rule of thirds is displayed in this image. The subjects are based at on the left side of the image and is balanced out by the plain wall they're leaning against. I'm not opposed to the negative space created by the wall though because of the subjects relationship to the wall. The boy is using the wall as support, just as the little girl is using the boy as support.
The emotion coming from the subjects also draws me in immediately. Her happiness and innocence comes off of the image and sits within the viewer and as you make your way up to the boys expression, it's more calm and almost protective. Some brothers ignore their little sisters but he's allowing her to cling onto him.
I like the lighting in the photo as well. It's natural and bright, which contrasts with the inside of the house, which is dark and has very little detail.
I believe the second best photo is this one because I love the look he's giving.
This is a close second because it hits almost all of the same points as the one above, except I believe the crop on the first one is better.
The innocence and protectiveness coming from the image go hand in hand instead of colliding like you would expect them too.