The correct answer is: Option 4. Mrs. Flowers’ words.
As the story centers in a conversation between the characters Mrs. Flowers and Mrs. Henderson, Mrs. Flowers openly expresses her concern over a certain individual by stating her own lack of necessity to logically understand Marguerite's current state of mind by "seeing inside her" (meaning to directly talk to Marguerite about her feelings) in order to tell something is wrong with her in that sense.
These words from Mrs. Flowers allow the reader to infer her concern over Marguerite.