Well, I don't think the addition of boob-like areas is really necessary to show that it is a girl. Especially when the character is like, 10 years old. I mean, c'mon..
Instead, I would focus on the hair as the more defining aspect of femininity. Some curves here and there, as well as emphasis on the skirt.
Here is my take on the subject.
This struck me as a shaman girl -in training- the moment I saw the sprite; she'd be seen collecting herbs for the real shaman, while avoiding the many dangers of the jungle around her village.
I steered the design to fit that imagining, loose robe and all, I guess. Take what you must.
Edit: I think the highlight on the hair might have been too much.