Personally, I would never give an 'okay' for someone to film a rape sceen with any underage performer, even the suggestion involving my own kids would envoke a near violent response.
I have seen plenty of movies where the act is depicted off camera or admitted to in some setting and as I recall those were very powerful dramatic moment's.
Filming the act no matter how 'tastefully done' makes me wonder what the hell the entertainment industry is thinking. I'm sure contraversy sells. And the DA of North Carolina (where, I understand, filming a simulated rape of a child is illegal) signed off on it as well. I really hope people respond by not seeing or purchasing the film.
I would personally like to see this Sundance film go the way of ZYZZYX ROAD