Miss Strangeworth feels that the town belongs to her and therefore that all the people are like tenants or vassals. She feels superior to all of them, and she gets special treatment from most of them because they are all a little bit afraid of her. As her name suggests, she is a little bit strange. A good example of how people respond to her is found in the scene in the grocery store. Although she makes only a few petty purchases, she expects deference and attentiveness from Mr. Lewis, the grocer.
"Imagine your forgetting that I always buy my tea on Tuesday," Miss Strangeworth said gently. "A quarter pound of tea, please, Mr. Lewis."
Miss Strangeworth feels that there is a great deal of evil in her town, but she doesn't know any specifics.
...as long as evil existed unchecked in the world, it was Miss Strangeworth's duty to keep her town alert to it.
This is why she writes her anonymous letters. She writes about the "possibility" of evil behavior without having a shred of evidence.
The town where she lived had to be kept clean and sweet, but people everywhere were lustful and evil and degraded, and needed to be watched; the world was so large, and there was only one Strangeworth left in it.
She is causing all kinds of trouble among the citizens of her town in her self-appointed role of moral guardian.
Many people seemed disturbed recently, Miss Strangeworth thought.
Her letters are provoking fear, suspicion, and unhappiness, but she has no idea that she is at the root of all this disturbance herself. She is obviously mentally unbalanced. She might be compared to Miss Emily Grierson in William Faulkner's story "A Rose for Emily." Miss Grierson is respected by everyone because of her ancestry and her dignity, but it turns out after she dies that she was a lunatic.
So Miss Strangeworth feels that the people around her are her responsibility because of her status as the oldest resident of the town and the last member of the prominent Strangeworth family. She feels it is her duty to supervise everyone in the town because any one of them is capable of evil behavior of one kind or another. She notices that her people seem "disturbed recently," but she does not suspect that she is the cause of the disturbance. Even after her famous roses are destroyed by Don Crane, she does not connect it with her poison-pen letter. She sees it as just another example of the wickedness of the world.
It would seem that the targets of Miss Strangeworth's anonymous letters are people of whom she feels a bit envious. Linda and Dave are in love. Has Miss Strangeworth ever been in love? Miss Foster has a nephew who looks after her. Does anybody look after Miss Strangeworth or care about her? Don and Helen Crane have a new baby they adore. Miss Strangeworth never had a baby or even a husband. Martha Harper has a husband, but maybe he has been cheating on her and everybody knows about it but Martha. There is a method in Miss Strangeworth's madness. She may not like to see anybody happy because she herself is unhappy. She is just a poor, lonely old woman who would like to be important.
The last sentence in the story begins with the words
She began to cry silently for the wickedness of the world...
Is she crying for the wickedness of the world, or for her roses, or for herself?