Nurse Carstairs

In the Miss Marple short story The Blue Geranium, Nurse Carstairs is a former nurse of Mary Pritchard, the invalid wife of George Pritchard.

Some time before the events leading to Mary's death, Nurse Carstairs was dismissed and replaced by Nurse Copling. Jean Instow, a friend of George Pritchard, thought the Carstairs was very pretty, and sympathetic to Mary's husband's plight. This was the cause of the row between the nurse and Mary and the cause of her dismissal. It was believed that she had recommented Zarida to Mrs. Pritchard, however when she was questioned by the police in their investigation of mrs. Pritchard's death, she denied all knowledge of the fortuneteller. It later turned out that it was Nurse Copling, who was Zarida, and likely recommented her. She probably lied about it being Carstair's recommendation to cover her tracks.

Portrayals
In the ITV 2010 adaptation of the novel (Episode 3, Season 5 of Agatha Christie's Marple), Nurse Carstairs is played by Rebekah Manning. She is given the first name "Susan" and her role is considerably enlarged in this adaptation. Here she actually did have an affair with George Pritchard. The cook Hester Milewater saw him teaching Susan a golf swing and then kissing her. Subsequently she became pregnant and George sent her away for this reason and installed her in an abandoned millhouse. Later she blackmailed George and wanted him to marry her (Miss Marple suggests that she was encouraged to do so by Nurse Copling). Carstairs was seen wearing an emerald ring. Mary Pritchard had earlier complained that one of her emerald rings had been stolen. Presumably George must have taken the ring and given it to Carstairs as a form of payoff. She was later found murdered, having been strangled with a tie belonging to George. In her room were various papers and a costume showing that she was the person who dressed up as Madame Zarida, the clairvoyant who had visited Mary Pritchard in order to frighten her to death. Miss Marple later surmised that that she had been framed by the real murderer, partly to incriminate George. At the time of her death, she was six months pregnant.

In the NHK adaptation The Blue Geranium, Episode 15 of their anime series Agatha Christie's Great Detectives Poirot and Marple, Nurse Carstairs also appears. She is dismissed by Mrs Pritchard but not because she suspected that George had designs on her. Here the two women had been using Tarot cards and Carstairs had drawn a death card. Mrs Pritchard had been frightened and asked her to leave. She does so willingly and without bitterness. She tells George that she believed in Tarot cards herself and understood Mrs Pritchard's feelings. She is brought back for the denouement but plays hardly any role in it.