Miss Brill is an older, unmarried Englishwoman living and working in France shortly after World War I. She seems to be living on a very limited income. Her plight reflects social reality: although it would not become fully apparent until the end of World War II, World War I ended England's century of world dominance. The war put the country deeply in debt and many English citizens saw a decline in their standards of living after the war. We see in Miss Brill, with her old but carefully cared for fox collar, her small, dark room, which is described as like a "cupboard," and her treat of a slice of honey cake on Sunday (she delights on the days when she finds an almond in it), a portrait of a woman trying to hang on to her dignity with a declining income in rapidly changing times. Her definition of what it is to be a lady is no longer the vogue; the world is passing her by.
In Katherine Mansfield's short story "Miss Brill", it appears that Miss Brill is from England. At one point in the story, we hear that Miss Brill would have a "queer, shy feeling at telling her English pupils how she spent her Sunday afternoons." Earlier in the story, she recalls watching "An Englishman and his wife".
It also appears, though, that Miss Brill is in France, given the reference to the "Jardins Publiques" (Public Gardens) in the story's opening line.