| Mrs Ferguson |
|Family|| Robert Ferguson (husband)|
Jack Ferguson (stepson)
|Behind the scenes|
|Appearances||"The Adventure of the Sussex Vampire"|
Mrs Ferguson is the second wife of Robert Ferguson and a suspect in The Adventure of the Sussex Vampire. The daughter of a Peruvian nitrate merchant, she moved to England after marrying Ferguson, but their relationship soon became strained due to her alien customs and Catholic religion. Her closest friend and seeming sole confidante is her Peruvian maid, Dolores. After her infant son's nurse apparently catches her sucking the blood from her son's neck, she is confined to her bedchamber while her husband seeks Sherlock Holmes's help in solving the mystery.
- Mrs Ferguson is never referred to by any name whatsoever in the story: she is only referred to as "my wife" throughout the story.