John Douglas divorces his wife, taking custody of their son Kenneth and leaving her with their little daughter Kathleen. Mrs. Douglas dies in poverty, and Kathleen falls in with crook Jack Baggot and his wife, who teach her how to pick pockets.

Mildred Vandeburg, an heiress who devotes her time to a hospital that she has built in the slums, breaks her engagement to her fiancé, T. Huntington Forbes, because Forbes is only interested in horses and sports. Meeda Jones, a nurse employed in Mildred's hospital, is married to a criminal named Spike, who steals some jewels and convinces his brother Dan to fence them for him. When Dan is killed as the police try to arrest him, his wife dies of shock, leaving their baby girl homeless. To help the baby, Mildred decides to take her to Forbes's home, where she informs her former fiancé that there is a "lady in the library" waiting for him.

In March 1916, Pathé released a short feature entitled Little Mary Sunshine, starring a four-year-old Marie Osborne. This was one of the first features ever directed by King and it was so successful that Pathé asked the original production company, Balboa, for five more features with the same child wonder. All were produced during the second half of 1916, and only three of them survive today – one being Twin Kiddies, which shows the amazing progress King had made since the first film in the series. Of course, the story is thin, the ending quite abrupt, and the opening sequences rather long. Yet, the direction is much more subtle, alternating between shots of different size, suggesting that King was mastering the art of composition.