*snickers* That was the best I could come up with on the fly: the main character is a preteen girl with a propensity for science and chemistry in general, and poisons and deductive reasoning in particular, who lives in a crumbling family mansion with her father and two older sisters outside a small small English village. I don't think they actually set a period, but the impression is post- WW 2. I've read three of them so far, one out of sequence, because the Used Book Store had it: "The Sweetness at the Bottom of the Pie", "The Weed that Strings the Hangman's Bag", and "Chimney Sweepers Come to Dust", and I've asked the Used Book Store to let me know if any of the others come in.