Francesca Annis as Frankie Derwent In the novel Why Didn't They Ask Evans?, Lady Frances "Frankie" Derwent is a plucky young woman. She is a friend of Bobby Jones. They solve a mystery together. She is the daughter of Lord Marchington, and has two brothers. Retrieved from "https://agathachristie.fandom.com/wiki/Frankie_Derwent?oldid=37237" Categories: Why Didn't They Ask Evans? characters Nobility Add category Cancel Save Community content is available under CC-BY-SA unless otherwise noted.