Does the world really need another Olsen sister? Up until last weekend, we're fairly certain that most movie-goers would have responded to that question with a resounding "no."

But then Sundance audiences got a chance to see Elizabeth Olsen in her pair of harrowing breakout performances in the indies 'Martha Marcy May Marlene' and 'Silent House.' Faster than you can say "John Stamos," Mary-Kate and Ashley's younger sibling has become the talk of two towns -- Park City, Utah, and Hollywood, Calif.

But who is this blushing young ingenue, a girl whose only screen credits prior to 2011 consisted of cameo roles in her overachieving sisters' direct-to-video and TV movies? Join us after the jump for all you need to know about the Sundance Film Festival's latest rising star.