After reading the posts on this thread, I realized that I'd not commented on the images themselves, but only made generalizations about the ouvere of the photographers.
The images are so different that at first it's difficult to compare them. But the common element is the little girls. Are they being shown as the principal subjects of the compositions, or only as adjunct elements to establish their relation to their enviroment?
In the Gedney photograph, the only hint is that bare light bulb. Without it the image might just as well (or better) be cropped to show the girls in their relaxed and comfortable hen-session. People will be people, and kids will be kids, regardless of their circumstance. Gedney has nicely and thoughtfully transcended that slice of "decisive moment" presentation. If it was an intentional inclusion then it is very impressive, but my gut feeling is that it just happened to be included because he had a wide-angle lens on his camera.
Adams presentation is somewhat more puzzling about what does it mean. I think that there is little or no intention to comment on relating the girls to the environment. It is intended only as a static portrait of them, and as such, taken out of context has, in itself, little interest. However, taken as only one element of Adams' deliberate style of work (with this family), it becomes the stronger of the two.