The Fallen Angel
This movie was released on July 28, 1918. Some scenes were filmed on California's Santa Catalina Island.
As you can probably guess from the title, this movie contains a strong moral lesson, and I'm guessing that plenty of moms took their daughters to see it. A young woman who works in a department store has an affair with her boss, a married man. After he passes away, she falls in love with a young man. However, when he learns about her past, he suggests that they shack up instead of getting married.
Here's one strongly worded review. "It rips away the purple, alluring mist of tawdry romance." – Tribune (Salt Lake City, Utah), August 18, 1918
No copies are known to exist.