She is also a highly respected treasure surveyor, jewell hunter and antiquity dealer; largely due to the fact she can steal whatever her clients are looking for. She is a distant descendant from the Moriarty bloodline, being the great-great-great-great-great granddaughter of Professor James Moriarty's niece, Gwendolyn Chambers.
Madeline resides in a mansion left to her by her late father, and operates her schemes out of the very dungeon chambers that her great (x5) grandmother and uncle once did. She holds herself in a very high regard and believes she is entitled to whatever she wants. This tendency gets her in trouble when it leads her to plans being ruined by Sherlock Holmes in episodes "The Dubious Spiritualist" and "Red Rising" . His actions force her to begin a relentless pursuit to discover something that can bring Sherlock Holmes to an end, once and for all. Or, as she puts it:
"He might appear to be on the side of the angels, but every family has skeletons in the closet".
Madeline Chambers has one half-sister, Elaine Chambers, who she famously tried to steal an antique watch off using a conman psychic trick. Elaine hired Holmes to track the watch down and his inquiries ended up leading him back to Madeline. Elaine disowned her sister there and then and the two have never spoken since.
The closest thing she could call a friend was her 2nd in command in "The Red Headed League", Rebecca Constance. They share a keen interest in money, jewels, and ripping people off. However, the pair still struggle to coexist at times, with both always looking for an excuse to mock the other.
However, even this did not last, as the group ends up disbanding after "The Sign of Things to Come", leaving Madeline friendless once again.
Madeline made two guest appearances during the first two series. Firstly in the 3rd episode of the 1st series "The Dubious Spiritualist", then again in the first episode of the 2nd series. She would later join the core cast full time from the start of the 3rd series and has been in every episode of the main series since.
Although not mentioned by name, she does appear in the NPLH novel "Of Shoes and Sherlock: The Diary of Miss Christine Blake", as "the little-red-headed girl" that Miss Blake keeps seeing watching the house.
Madeline and Rebecca also feature as one of the cards in the Sherlock Holmes trading card game "The Grand Game"
- "Shut up"
- "It's mine"
- "Oh, Bloody Hell!"