I find absolutely nothing wrong with the makeup. It's just fake eyelashes. It's an absolutely stunning photo. Honestly, this is not sexualizing a child in any way. Your sexual thoughts are what's sexualizing her. I seriously doubt that she wears that makeup on a day to day basis. It's adding more affect to the photo. And there's a lot worse out there, like the child beauty pageants. I'm a dancer and I act on occasion, and honestly, some little actors and dancers have to wear a little bit more makeup than that so that their eyes can be seen on stage. I see absolutely nothing wrong with that. What I do find wrong is shaming someone for their artwork and beautiful talent in photography. This is a gorgeous photo. I personally don't like fake eyelashes, but they seriously add drama to the photo. I don't care how young she is. The eyelashes are well-used in this photo.
This is a wonderful, wonderful piece of art and an absolutely beautiful little girl.