He has a brother who appears in some of the stories. His name is Mycroft.
No, Sherlock Holmes and Dr. John Watson are not blood relatives. They are close friends and colleagues who share a strong bond through their work as detective partners in Sir Arthur Conan Doyle's stories.
Sherlock Holmes' real name is Sherlock Holmes.
Sherlock Holmes 3
.... Sherlock Holmes
Sherlock Holmes.
Sherlock Holmes
"Young Sherlock Holmes" (1985). Stars Nicholas Rowe as Sherlock Holmes, Alan Cox as John Watson.
Sherlock Holmes's is the more proper form though Sherlock Holmes' is also acceptable. Please check the link below.
We are not told about any of Sherlock Holmes' female relatives except his grandmother, who was the sister of Vernet, the French artist (with no further details) if that is what you are asking about.
Robert Downey jr has been in two Sherlock Holmes movies: Sherlock Holmes (2009) and Sherlock Holmes: A Game of Shadows (2011)
Sherlock & Holmes
The Adventures of Sherlock Holmes