In the novel 4.50 from Paddington, Anna Stravinska was the stage name of the first victim. She was strangled in a train carriage.
Anna is only alive for a few pages, she was on a train when she was murdered by a unknown man, while the shocked Elspeth McGillicuddy watched in horror from her own train carriage. After Miss Marple is able to trace the journey, she realises that Anna's body might have been shoved out of the train door while passing Rutherford Hall. So she gets her friend Lucy Eyelesbarrow to work as Cook/Housekeeper for the Crackenthorpes. While playing golf on her day off Lucy finds traces of a fur coat and a compact chose to the train tracks, this means to Jane that the murderer knows the estate and the victim's body has been hidden on the grounds. Looking in the stables filled with questionable antiques Lucy finds the body in a sarcophagus.
Inspector Craddock and the police find that the body's clothes were French. Emma Crackenthorpe suggests that the woman might Martine, who was the Wartime fiancée of Edmund (the oldest son now deceased). After the war they received a letter from her claiming she had Edmund's child and wants support for him. However, Martine is found to be alive and is the mother of Alexander's school friend. While contracting the French police Craddock finds a led in the form of a missing person who was dancing with the Ballet Maritski, contracting the director Madame Joilet they find out she had a husband and was a good Catholic.
Jane then gets Mrs McGillicuddy to come to Rutherford Hall to tea, she then choked and Dr Quimper went to inspect her throat and when her friend came in she saw Quimper holding Jane's throat and declares he was the man who she saw killing Anna. They then reveals that he was Anna's husband they had been separated, but when he wanted to marry Emma he spoke to her on the train she refused to divorce him due to religion and so he murdered her just as the train passed the estate.
Murder She Said
She appears in the 1961 Movie played by Nadia Pavlova, the changes is that Miss Marple witnessed the murder and takes the job at the Hall, Alexander finds a musical compact and Jane uses it to trap Quimper. She also reveals that his use of Martine was wasted as the said woman was a hard working farm girl and the victim had never done such things.
1987 BBC Version
In BBC's 1987 adaptation of 4.50 from Paddington, the storyline involving Mrs Stoddart West as "Martine" is cut out and part of the role given to Anna to create a significant misdirection for the course of the police investigations.
In this adaptation, Emma Crackenthorpe does receive a letter from one "Martine", claiming to be the wife of Edmund Crackenthorpe. The pathologist noted a high degree of muscle tone on the dead body of Anna. From this and the kind of clothing she wore, Miss Marple inferred that she might be a dancer. Her troupe is traced and found to be the Ballet Maritska. When Chief Inspector Duckham investigates her background, he learns from her colleagues at the Ballet Maritska that her real name is Martine Isabelle Perrault and that she had "a man" in her past life. She had moved to London in the hope of coming together with her husband again. Duckham then learns that someone has broken into her house to remove all traces of her background and true identity.
Duckham speculates that Anna was the "Martine" in the letter, which would make her a potential claimant to the will. Of all the suspects threatened by this new fact, Duckham focusses on Harold Crackenthorpe who faces the most immediate threat. His creditors had loaned his bank money on the prospect of him inheriting from the will. If the inheritance is jeopardised or reduced, they could foreclose. So Harold murdered Anna. But when Anna's body is discovered, he might have realised that he would be exposed, so he committed suicide and faked it as an accident so that his wife could claim the insurance. Miss Marple, however, disagrees with this because she doubts Harold really loved his wife to the extent of taking elaborate steps to ensure his wife would get his insurance payout. Miss Marple proves from Somerset House records that Anna was Dr Quimper's wife. He had faked the letter from "Martine" as he knew Edmund's relationship with someone of this name. Miss Marple also surmised that Anna's death is linked to the killing of Harold Crackenthorpe. He was an enthusiast of watching ballet performances he would be familiar with the dancers and might have recognised Anna and might have hinted as much to Quimper. The motive for her murder is finally confirmed when Miss Marple obtains a document from Somerset House proving that Anna was the wife of Quimper.
The part of Anna is played by Juliette Mole. We only see her briefly at the beginning where she is praying in a church and then being followed by an unknown man down the London streets. The best visual of her is from a photo which her friend Francoise shows to Inspector Duckham.
2004 ITV Version
In the episode she was played by Meritxell Lavanchy, her real name is Suzanne Bellaine, she is found in a mausoleum rather than a stable. Quimper plants a fake clue to push people away but he spotted by Alfred who upon realising what he saw blackmailed Quimper which resulted in his death. There was focus on Anna's body being muscular and clearly not a mother's body. The reveal is done on a train to recreate the moment for Mrs. McGillicuddy.