You have captured the curiosity of the children well, and wonderful interaction between those in the group. The solitary child off to the left makes me feel rather sad; I am sure he isn't really cast out, just passing by, but that was the emotion that was evoked in me on first viewing. A cool idea for a poster, and a text that has clearly been inspired by the photo.
A very interesting image, and an interesting composition, that does work well with the title and phrase you have chosen to put with it. The colours are vibrant and really good, maybe the crop ont he right should have had all the end girl in the photo, but overall a very good end product.
In my belief there are more things that contribute for a great motivational/de-motivational poster:
Idea/creativity:6
Quality of the photo:10
Artistic viewpoint:6 Maybe only one subject (looking at them) was enough
Frame/borders:10
Appealence of the font:10
Average: 8.4 (8)