To cleanse my palate, here's a story about Helen and Julia Stoner. It's set on the same day that Watson reads Holmes's "Book of Life" article and learns that he is a consulting detective. I may include this fic as part of the chapter covering STUD, or I may hold it back as a flashback/memory that Helen has after SPEC, because she feels guilty about not believing Julia's suspicions about Dr. Roylott.
I have given Helen a middle name of Enid, because that is her name in Doyle's 1910 Speckled Band play. Also, I should note that I previously made up a backstory where the twins were 12 years old at the time that Roylott beat the native butler to death, and that Julia witnessed it. Helen ran away in fright, the mother (whom I named Fidelia) ran to call for help from the police, some male servants tried to get Roylott to stop, and a maid forcibly tried to drag Julia from the room. Julia refused to go or to have her eyes covered. Instead she fiercely yelled at Dr. Roylott as being a horrible monster, nothing like her real (long-dead) father. Roylott almost came over to beat her too, but returned to the butler because the other servants were trying to take him away. Roylott then savagely bashed his head in. Julia watched in horror, then fainted, and since then her hair grew white in a patch above her right temple. Roylott was convicted and served a long prison sentence in India. But he made excuses to his wife about his inherited temper, and promised that he would never do any harm to her or the girls. Then a dozen years later Roylott was released from prison and the family moved to England, so that Roylott could try to start a practice in London. But Fidelia died in a railway accident in 1875, and Roylott immediately brought the girls to Stoke Moran. They would have been 24 at the time, and eligible for marriage.