Madison Hunter, mostly referred to as Miss Hunter and Maddie is the childhood friend of John Watson. She is the half-sister of Irene Adler through their mothers, who is American. Madison’s father is British, meaning that Madison is half-British, half-American descent.
Instead of her being a love interest of Doctor Watson, Madison acts as love interest of Sherlock Holmes.
Irene is Hunter’s half-sister, sharing the same mother but different fathers. Their mother is Isabelle Adler, who in return is the wife of Madison’s step-father, Joseph Adler. While Irene was raised by her mother, Madison was raised by her father. Irene seems to merge in with Madison’s brother and sister from the original novels.
Watson and Hunter have been best friends since they were children and it isn’t all it's cracked up to be when they meet Sherlock Holmes for the first time. They do not feel any love towards one another and only feel a mutual friendship.
Instead of the original Doctor Watson acting as a love interest for Miss Hunter, she finds herself attracted to her half-sister’s love interest, Sherlock Holmes. Together, they have a child together, even Sherlock knew by reading the signs of Madison’s change in nature.
Role in A Game of ShadowsEdit
In A Game of Shadows, Madison learns she is pregnant with Holmes’ child; however she keeps it to herself in fear that she and the baby are harmed because James Moriarty is on the loose. Later on when Sherlock and Moriarty supposedly fall to their deaths, Madison is oblivious of her lover’s survival. However, Mycroft is told by his younger brother to look after Hunter and the baby while he is away before he can reunite with her. Watson and Mary also cancel their honeymoon trip when Madison goes into labor eight months later to give birth to a baby boy she names after his supposedly late father, Sherlock Holmes and the baby has Watson’s first name as a middle-name.