Head in the Clouds

In a prologue, young Gilda Bessé, the daughter of a French aristocrat and an emotionally unstable American mother, reluctantly is told the life line on her palm doesn't extend past the age of thirty-four by a fortune teller. Fast forward to a rainy night in 1933, when she stumbles into the room of Guy Malyon, a working-class Irishman who is a first-year student on scholarship at Cambridge University. She has had a lover's quarrel with one of the dons, and rather than turn her out into the storm, Guy gallantly allows her to spend the night. Later, they become lovers, but the two are separated when Gilda's mother dies and she opts to leave England. Several years later, Guy sees her as an extra in a Hollywood film, and shortly after he coincidentally receives a letter from her inviting him to visit her in Paris, where she's working as a photographer.He discovers she is living with the Spanish-born nursing student/model Mia and has a lover, whom she quickly discards when Guy moves in. The trio are enjoying their unusual living arrangement, but world events are beginning to affect their existence. It is the height of the Spanish Civil War, and idealistic Guy, a long-time supporter of the army of the Second Spanish Republic, is determined to do what he can to help them as Francisco Franco's fascists gain strength. Mia, too, is anxious to come to the aid of her native land. Gilda, however, has no interest in politics or anything else that might disrupt her life of luxury, and pleads with the two to ignore the conflict, but they feel compelled to act and depart for Spain.Guy becomes a soldier, while Mia tends to the wounded. They cross paths one night and, before making love to Guy, Mia confesses she was Gilda's lover. In the morning, her ambulance is destroyed by a land mine, and after laying her to rest, Guy returns to Paris, where he is ignored by Gilda, who feels his abandonment of her was a form of betrayal.Six years later, Guy is working as a spy with the underground in occupied Paris under the auspices of British intelligence. He learns Gilda has taken Nazi Major Franz Bietrich as a lover and visits her in their old apartment, where the two make love. The following morning she tells him their affair is over and the two never can see each other again. D-Day is approaching, and Guy throws himself into his work. One day he arrives at a café to meet a contact, but instead is approached by Gilda, who has overheard her German lover's plotting a trap and has come to help him escape in cleric's clothing she has concealed in the restaurant's washroom. That night, he and his associates destroy a rail station, but only Guy manages to elude the German soldiers.Guy returns to London, where he discovers Gilda joined the Resistance a few years earlier. With the occupation of Paris having come to an end, he realizes the locals, who long regarded Gilda as a Nazi sympathizer and traitor, will seek revenge for what they perceive to be her lack of loyalty and patriotism. As he returns to Paris to find her, Guy is unaware Bietrich has been killed in Gilda's apartment and she has been taken captive by a mob intent on avenging the deaths of their loved ones.

Question: Why does Gilda leave England?
Answer: Her mother dies