What is the first name of the person tries to ensure that her two children never see their father again?  Answer the above question based on the context below:  Nathalie Stein, an embittered and exhausted young woman, is currently going through a bitter divorce from her husband Tim. A qualified attorney, she is doing her best to ensure that her two children, Jeremy and Elisabeth, never see their father again. Tim arrives to pick the children up for what is believed to be one last time. He fails to return with the children. Nathalie's dog disappears under mysterious circumstances and she then discovers a piece of paper with the word "Dard" (the Persian word for "to inflict pain") written in blood in her house. Panicked, she calls the police, who cannot help without more evidence of a crime. She decides to meet Tim and the children in Chinatown, but they do not show up. In the evening, Tim suddenly appears at the house, apparently badly injured. Before dying, he tells Nathalie that the children have been abducted. She immediately informs the police, but when the detective, James Gates, arrives, the body is gone and the site has been cleaned up leaving no evidence that Nathalie is telling the truth. Later a police officer, Phil Warren arrives to question Nathalie. Warren is revealed to be corrupt and overpowers Nathalie. Graphically depicted in flashback, he tells Nathalie that Tim had been hired by the Persian Mafioso Maho and had burst in on a drug deal organised by Maho, killing those present before running off with a million dollars in cash and the cocaine. Convinced that the drugs are hidden in the house, he tells her he has killed her son Jeremy with a chainsaw and will kill Elisabeth as well if he is not told where drugs and money are, Warren then tortures Nathalie in an attempt to get the information out of her, cutting off a finger and a toe with pruning shears. Nathalie eventually manages to break free and kills Warren with a broken bottle.
Answer:
Nathalie