I would have turned the camera to portrait orientation. I think the camera's tone curve (aka contrast setting) is a bit too harsh, and that is what caused the burn-out on her white shirt. Shaded lighting like that really is not all that harsh, especially when a bit of flash was used as in this situation.
Going by her apparent age, it looks like the little girl might be at that gap-toothed age/stage where many kids are reluctant to show their teeth...regardless of her motivation, she seems like she's not too keen on being photographed. Some day though, this could become a cherished photograph, however, and it's not "horrible" or anything.