the eyes sometime play trick on us. With me, i think the ANBU girl is Rin. Why? Well to end the discussion, i try to draw them out on the clear plastic sheet to compare their ananomy structures. quess what? More than 90% of their face structure mach or closely match, few change but not very sufficient, like the hair color, and the mark on her cheeks. Therefore, there are only 2 theory left, 1 is that the author's faul or at least the painter faul for draw them too identical, in that case Rin death and Anbu girl is someone else, and the other is that anbu girl is Rin.