I think the people who made the previous comments didn't realize that Aang is supposed to be older, considering the necklace and cape he has on.
This is really cool, I love that Zuko is in the picture, too. I love how you drew Katara's hair (She also looks very well represented and strong, the side profile view and everything!), and Toph looks so realistic! Aang looks very Aangy and cool, too! Lovely!