Zilton does have a point, children are sexualized by their parents at times, even in western culture, and it's considered "normal." For "art," usually. There is a weird double standard and it's difficult to place exactly where the line is drawn.
I hope you don't condone things like JonBenÃ©t Ramsey's modeling. I certainly don't.
Either way, I'm curious as to why Gust has been going for a younger look recently. I mean, obviously to appease some of their fans, but when you compare it to more of the original games, I'd say the design quality has gone down, despite actually visually looking better. If you compare earlier Gust games, like Marie and Elie, they looked young, but not like 13-year olds. Judie and Violet both look much older, by at least 3-4 years. Then compare that design to the new Atelier game's design, where the heroine looks 12 or so (well, in the defense of Gust, she might possibly be 12).
It's more than something just happening in Ar tonelico, but in their flagship Atelier as well.