This is the pink shirt that Rosalee is wearing in the Season 3 episode "Blonde Ambition" (3.22). The label inside says "Rosalee 1/2" (that is the way production identified their items - 1 out of 2). Since it is the first of two identical items, I am fairly confident this is the one seen in picture 3 and 4 (thanks to screencapped.net!).
