The Question and Answer section for The Turn of the Screw is a great resource to ask questions, find answers, and discuss the novel.
Douglas knew and was in love with the governess as a young man, when she was his sister's governess. This may bias his description of her. He has kept her manuscript in a locked drawer in his home for many decades.
In the prologue, Friends gathered around a fire in a country house outside London on Christmas Eve entertain themselves by telling ghost stories. There does not seem to be a date or place.
Which character are you referring to?