In The Murder at the Vicarage, Mrs Price-Ridley puts a pound note into the offering bag on the anniversary of her son's death. When the amount of the collection is posted up, she sees that a ten-shilling note is the highest item mentioned, and becomes upset. She complains to Colonel Protheroe, who then decides to go over the Church accounts.
On the evening of the murder, Mrs Price-Ridley receives a telephone call from someone calling themselves The Avenger. The caller calls her a " wicked scandal-mongering old woman", tells her that Scotland Yard are after her for libel, and warns her to hold her tongue in the future. Mrs Price-Ridley is very upset, and reports the matter to the police. She also reports that she heard a shot from the woods at about half past six that evening.
Mrs Price-Ridley later tells Reverend Clement that on the day of the murder, her maid heard a sneeze from the direction of the vicarage. Mrs Price-Ridley was of the opinion that the murderer had concealed himself in the bushes, waiting for an opportunity to enter the vicarage.
Miss Marple later explains that the telephone call that Mrs Price-Ridley received was from Griselda Clement. Mrs Price-Ridley had been going about hinting that Reverend Clement was responsible for the money that was missing from the church funds. Miss Marple thought it likely that Griselda and Dennis had heard the rumours Mrs Price-Ridley had been circulating, and thought of this way to silence her.
Miss Marple also suggests that the sneeze which Mrs Price-Ridley's maid heard was really the sound of the shot that killed Colonel Protheroe, if the gun had a silencer on it.
In The Body in the Library, Mrs Price-Ridley hears from her maid, Clara, that a woman's body was found in Colonel Bantry's library. Mrs Price-Ridley goes to the vicarage to ask for Reverend Leonard Clement's advice. She tells him that she met Colonel Bantry on the train going up to London, and he had buried himself behind a newspaper, as if he did not want to talk. At Paddington, he got into a taxi, and she heard him give the driver an address in St. John's Wood. She considered this behaviour suspicious.
- The Murder at the Vicarage (1930)
- The Body in the Library (1942)
- The Case of the Perfect Maid (1942)
- In the Miss Marple 1986 episode The Murder at the Vicarage Martha Price-Ridley is played by actress Rosalie Crutchley. In this adaptation, she does not receive a telephone call telling her to stop spreading rumours. However, she goes to the police to report that there was a man in her shrubbery on the day of the murder, and she distinctly heard him sneeze.
- In the ITV adaptation of The Murder at the Vicarage the character is renamed Marjorie Price-Ridley and is played by Miriam Margolyes.