Yes, that's Gold Medalist Missy Franklin. She stops by this episode of Pretty Little Liars.
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Pretty Little Liars Season 3 Episode 22 Quotes

You know, Emily, sometimes you poke the bear, and other times the bear pokes. *sigh* It's from a movie.

Hanna

Spencer: Why do you even bother coming to church?
Ali: I like to cover my bets.