In Le Crime est notre affaire the 2008 French adaptation by Pascal Thomas of 4.50 from Paddington, Edmond Charpentier is the parallel of Edmund Crackenthorpe in the original novel. He is the eldest son of the family patriach Roderick Charpentier but he is already dead during the time of the events in the plot.
According Emma Charpentier, Edmond was her favorite brother. He had died sometime during "the war". Considering that the plot is set in the 21st century, this would have to be a war in the 1990s such as the Gulf War. For the purposes of the plot, it is Edmond's wife that is significant. Emma reveals the police that Edmund had written to her just shortly before his death to say that he had met a Russian woman named "Martina" and they were getting married. A few weeks before the events in the plot, Emma received another letter, this time from "Martina Charpentier", claiming to be living in Lyons and that she has a son but doesn't have the means to raise him. Emma invited her to the house but she never came.
For a while, police investigations focussed on the possibility that the dead woman found on the grounds of the chateau could be this Martina and that someone in the family had murdered her because they did not want another claimant to the family fortune. Only much later is it revealed that Martina is alive and well. She had indeed married Edmond when they met in Damascus but they had split up and she had married someone else.