Task: Question Answering
Input (English): Passage: A Bill of Divorcement describes a day in the lives of a middle-aged Englishwoman named Margaret "Meg" Fairfield; her daughter Sydney; Sydney's fiancé Kit Humphreys; Meg's fiancé Gray Meredith; and Meg's husband Hilary, who escapes after spending almost twenty years in a mental hospital.  After the family discusses Hilary's genetic predisposition toward psychiatric problems, which Sydney seems to have inherited, Hilary and Sydney give up Meg and Kit in order to avoid passing this trait to future generations.
The film begins on Christmas Eve as Meg gives a party in her comfortable English manor.  In addition to dancing and listening to Christmas carols, Sydney and Kit happily discuss their future together, as do Meg and Gray.  The only unpleasant moment of the evening occurs when the singers dedicate their performance of God Bless the Master of This House to Gray.  Hilary's sister Hester objects to this because she considers Hilary to be the master of the house even though he is psychotic and institutionalized.
On Christmas morning, while Meg and Gray are at church, the asylum telephones to say that Hilary has gone missing, and Hester unintentionally reveals to Sydney that insanity runs in their family.  The family's official explanation of Hilary's troubles has been that he experienced shell shock while fighting in World War I, but another family member had similar problems in the past.
Hester and Sydney discuss Hilary's talent as a composer, and Sydney sits down at the piano to play an unfinished sonata that Hilary wrote before going to war.  A few minutes later, Hilary returns home, having escaped from the asylum.  He meets Sydney and they chat comfortably, except for a heated argument that serves to further display their similarities as sensitive, free-spirited individuals. 
Question: Who does Sydney find out about the families mental illness from?
Output (English): Hester.