Sher Holmes

Sherlock John "Sher" Holmes-Hunter, sometimes referred to as Sherlock Holmes, Jr. is the son of Madison Hunter and Sherlock Holmes, the nephew of the late Irene Adler and Mycroft Holmes, and the godson of Mary Morstan and John Watson.

He was named after his father and godfather, respectively.

A Game of Shadows
His mother Madison learns she is pregnant with Holmes' child; however, she keeps it a secret from Holmes until Moriarty is off of the streets and "rots in a jail cell". However, she does confess it to Mary, who promises not to tell for the sake of her friend and Madison's unborn child. Later, when Sherlock Holmes fakes his death, he knew the entire time Madison was pregnant, but didn’t say a word. Eight months later, Sherlock, Jr. is born at the end of A Game of Shadows, where his father Sherlock is presumed deceased. His mother goes into labor eight months after Mary and John return from their honeymoon. In her flat of 221b Baker Street, John delivers the baby himself because he was an ex-army doctor.

Trivia

 * Sher seems to be the 2009 film version of Lucy Watson, a daughter of Madison Hunter in the original novels but instead of the son of John Watson, Sher is the son of Sherlock Holmes as opposed to his mother's childhood friend.