“The Killing” thesp Katie Findlay has landed the female lead opposite John Karna in FilmNation Entertainment’s teen comedy “Premature.”Dan Beers is directing from a script he co-wrote with Matthew Harawitz. Aaron Ryder and Karen Lunder are producing for FilmNation. Karna (“Bindlestiffs”) will star as a high school student who begins testing the boundaries when he finds his epic day repeating itself. Findlay will play his best friend. Findlay, who plays murdered teen Rosie Larsen on AMC’s hit series “The Killing,” recently wrapped John Huddles’ indie “The Philosophers.” She’s repped by Pacific Artists Management and Thruline Entertainment.