In Je ne suis pas coupable, the France Télévisions adaptation of Sad Cypress for the TV series Les Petits Meurtres d'Agatha Christie, Melle Thuleau is the nurse of the elderly millionaire Élisabeth Laroche-Viseul. Her role in the adaptation is a hybrid character that parallels both Nurse Eileen O'Brien and Nurse Jessie Hopkins.
Like the two nurses in the original, she takes care of Élisabeth. She also complains of a missing vial of morphine just like Nurse Hopkins, although it is not clear whether this plot element is developed. It could have been the drug used to knock out commissaire Larosière and Louis Servais who were keeping watch over Élisabeth. The old lady was herself also drugged before being suffocated to death. However one scene shows drops of a red liquid being added to the coffee pot and it is not clear that this is morphine. Clémence Mouson, the Mary Gerrard parallel is not killed by morphine poisoning either, like in the original. Here she is stabbed with a pair of scissors.
After the death of Élisabeth, Claire Laroche-Viseul as her heir, awards the nurse Thuleau a sum of 50,000 francs. There she would have faded out of the picture had not Larosière and Lampion pressed on with their investigation. After Claire is arrested, tried and sentenced for the murder of Élisabeth as well as Clémence, Lampion discovers that the gardener Fernand (Clémence's adoptive father) died in a car accident driving an expensive car. Someone is buying his silence in the affair but why? Believing that they may have missed something, Larosière and Lampion return to the crime scene and search Fernand's house. They find a postcode with an Australian postmark which Larosière, a former stamp collector, recognises as false. Then Lampion discovers that a picture on the wall with Fernand, his wife and his wife's sister, is now missing. They next learn that Clémence had made a will leaving her estate to her aunt, one Alexina Cuvier, Fernand's wife's sister, who had apparently gone to Australia. Larosière and Lampion set a trap for this Alexina by publishing fake news announcements that Claire had been executed. When Alexina turns up at the lawyer's office to claim her inheritance, she is surprised to meet, instead, Larosière and Lampion, who, of course, met her previously as Melle Thuleau.
Thuleau's plan, as recounted by Lampion, ran along the same lines as Jessie Hopkins in the original. She had heard about Clémence being the daughter of Élisabeth Laroche-Viseul from her sister. She then came back to France to get a job working for Élisabeth under the name of Melle Thuleau, not a difficult feat, she tells the police, because Élisabeth was a difficult person and no one could work for her for very long. In the meantime Thuleau kept up the impression of still being in Australia, hence the postcard with the fake postmark.
In this adaptation, Thuleau killed Clémence by stabbing her with scissors. There poisoning/emetic method, used to cast suspicion on Elinor Carlisle in the original is not adopted. There is already plenty of grounds for suspicion on Claire--her difficult relationship with her mother, the fact that she learnt that Clémence is also her mother's daughter, and her natural jealousy with Clémence for taking her fiance Mathieu Vidal. Thuleau only needs to add to this by telling the police that she heard Claire threaten to kill Mathieu and Clémence, words uttered during an argument after Mathieu broke off the engagement.