Rose Waters is a non-canonical character created for the Agatha Christie's Marple adaptation By the Pricking of My Thumbs. She is the daughter of the local doctor in the village of Farrell St Edmund, Dr Joshua Waters and works for Hannah Beresford at the "Bull and Butcher" inn.
Rose's main role is in a sideplot which involves a love triangle between her, an American serviceman named Chris Murphy and the village constable Ethan Maxwell. Her backstory intersects with the main plot because, as Miss Marple and Tuppence would discover, Rose had a twin sister Lily Waters who disappeared when very young and was later found murdered. Miss Marple and Tuppence suspect that the disappearance of Mrs Lancaster may have to do with an attempt by the murderer of Lily Waters to cover up the tracks.
In the course of the episode, Rose discovers a note from one Sylvia making an appointment with Chris. This causes a misunderstanding between her and Chris and leads to her accepting a proposal of marriage from Ethan. Sylvia turns out to be Chris's English mother. With some help from Miss Marple, Rose and Chris are reunited at the end. Dr Waters at first does not approve of his daughter's relationship with Chris as he fears she would move away but he beccomes cheerful at the end when Chris tells him that he intends to marry Rose and settle down in the village.
Rose Waters is portrayed by Michelle Ryan.