This article contains fan theories about Adelaide Langdon. It is separate to avoid contaminating the main page with spoilers and speculation. It is subjective.
Deprecated Subpage
This article theories subpage has been deprecated, and should be moved to individual theories in the Theory: namespace.
Theory #1: Adelaide is a (now deceased) human Edit
CONFIRMED: Adelaide died in "Halloween: Part 1" in a hit and run accident. She did not die on the property, and told Constance, through Billie Dean, that she was glad because she is afraid of Tate after learning what he'd done.
Theory #2: Adelaide is more than one individual Edit
The Family Portrait website has an interactive element, and when The Daughters Adelaide are clicked, it shows a row of identical doll heads and a mold for a doll's head. This is not something that would have been in the specimen basement. Is this a hint that Constance created Adelaides like dolls? It would explain why Constance was so protective of her: She has no identification, yet Constance also somewhat mentions being pregnant with Addie. Was she lying?
In the Family Portrait site the younger Adelaide daughter is holding a doll that is wearing the same dress as her. Perhaps they were twins, one died at a young age and Constance (or some other power) trapped her soul in the doll?
Let's assume there is only one Adelaide, and that she ages like a normal human. (Down Syndrome does not slow one's aging.) She's clearly over 5 and under 10 years old in 1978. That would make her born between 1968 and 1973, which would make her 38 to 43 in 2011, the show's present. She looks 30-35. Constance said in Halloween, Part 1 that she'd been dealing with Adelaide for "30 some odd" years, not 40. Adelaide was very cagey with her response to Violet about her age in the same episode. How old is she really?