Desc: The Big Sister: Directed by John B. O'Brien. With Mae Murray, Matty Roubert, Harry C. Browne, Ida Darling. A daughter of the slums has a little brother and makes a brave attempt to earn enough for both herself and Jimmy after her father is sent to jail on a fake charge trumped-up by "Nifty" Mendez, who is very anxious to get her in his toils. Betty escapes from the city and Nifty. On the road Jimmy is struck by Rodney Channing's motor. The injury is not serious but Jimmy must remain in Channing's home for some time. During the visit, love grows up between Channing and Betty, who is now of course very happy. But a newspaper announcement and the author send Nifty again into her life and simultaneously with his entrance comes the exit of happiness. Betty fears to tell her fiance that her father is in jail, so she gives Nifty the pearl necklace lately presented to her and leaves the wonderful home. "As the days pass" however, Channing's cousin finds it necessary to visit a modiste's shop in search of a wedding gown and Channing accompanies the bride-to-be. There he finds Betty, for she is the model who displays the gown.