My understanding of it, (from reading John Baxter's biography of De Niro) is that Jody Foster herself was the one who wanted her sister to do the scenes, as playing such a young whore doing such things so comfortably was hard for her to take.
Mick
...dot com bold typeface rhetoric. You go clickety click and get your head split. 'The hell you look like on a message board Discussing whether or not the Brother is hardcore?
