One of the most famous sister duos — yes, that Olsen duo — has a younger sister. It's an Olsen trio! We expect rising actress Elizabeth Olsen to be in the spotlight a lot more, particularly after two impressive style debuts at Cannes Film Fest. Showing her sibling loyalty by wearing The Row, Elizabeth chose a white beaded dress for a daytime appearance, then followed it up with a sexier black dress — with the season's "it" dress trend, the thigh-high slit — also from The Row. Click the slideshow to see more angles on the Olsens' youngest sister.