What are the themes of the story "Miss Esther's Guest"?

Many of Sarah Jewett's stories focus upon country life in New England at a certain point in time: they attempt to offer a sympathetic and intimate view into the lives of people from this region. This one is no exception, but it also touches more specifically upon several other themes particular to its protagonist.
Miss Esther Porley has lived a fairly sheltered life. Although she is well known in the town, and much-liked, she is also clearly removed from other people due to being a single woman living on her own, and approaching old age. Although Miss Esther, at sixty four, thinks of age as still being in the future for her, old age and the loneliness of old age are a major theme in this story.
The slow changes occasioned by old age are symbolized at the beginning of the story through the descriptions of Miss Porley's belongings: the "tender spot in the silk" of her old shawl, the "wave in the looking glass" which makes it difficult for her to straighten her bonnet, and the crack in her "well-darned silk glove." Esther is able to conceal all these various flaws well enough to her own satisfaction—she is content that she can appear in public without any of these flaws being obvious and embarrassing. In this way, the flaws represent her own concealed loneliness, growing as it is with the increases of age. The people who meet her do, of course, notice—when Esther asks Mrs. Wayton if there is anything she can do, Mrs. Wayton does not want Esther to feel that she is indeed a "poor tool," isolated, old and useless, so she gives her something to do. People respond to Esther's age and loneliness, however she seeks to conceal them.
Old age and loneliness are represented, too, in the person of Mr. Rill, whose eyes have given out and who lives alone getting ever "stiffer and clumsier." Like Esther, he struggles to support himself on his own, and has no wish to be a burden to anyone—when it becomes clear that Esther was expecting a woman, he immediately volunteers to go elsewhere so as not to be an inconvenience.
At the end of the story, however, the two old, lonely people have found comfort in each other, a representation of another theme in the story: the importance of reaching out beyond our comfort zone. Mr. Rill is not comfortable being a possible inconvenience upon Esther. Esther is afraid to have a man in her house and is initially "enraged" with the Committee for sending Mr. Rill to her. Both of these older people are very wedded to their own ways of doing things. However, when circumstances force them together, they discover that change is possible. Rather than resisting change, they allow themselves to be open to it, and find that this is the key to defeating their mutual loneliness.