Miss Sweetstory was first mentioned on April 9, 1971. Snoopy reads her Bunny Wunny book, and, thinking it is the most exciting book he has ever read, decides to write a letter to the author. The next day, while Snoopy is writing his letter to her, he reveals that it is not a normal fan letter, but a love letter because he has fallen in love with Miss Sweetstory. When Snoopy gets a return letter from her, he is very excited to hold a letter which Miss Sweetstory has touched. It turns out that all the letter says is "Dear friend, Thank you for your letter. Sincerley, Helen Sweetstory". Lucy tries to convince Snoopy that it is a form letter, but Snoopy insists that she does not understand love. However, Snoopy's love for her comes to a halt when he finds out that she owns twenty-four cats, and he gives his whole series of books to Linus.
Early the next year, on February 11, 1972, Snoopy writes a letter to Miss Sweetstory again, saying that he wants to write her biography and asking if he can meet her and interview her. He requests that she lock up her cats before he arrives. Charlie Brown points out that Snoopy does not know where Helen Sweetstory lives but the beagle is certain that she lives in a "white vine-covered cottage with rose bushes, a picket fence and a willow tree" and that he will recognize her house when he sees it. He and his secretary Woodstock go to meet her, eventually finding a cottage exactly like the one which Snoopy had imagined. After Snoopy returns home, he begins to write the biography of Helen Sweetsory. He writes about her birth, decides that the next few years were boring, and skips to her high school prom. The remainder of the biography consists of a series of unconnected sentences. Snoopy insists that he is being a gentleman by not giving away the intimate details of Miss Sweetstory's life, however, the biography makes little sense. In the strip from March 3, 1972, Charlie Brown asks Snoopy for his opinion about a newspaper article in which Helen Sweetstory denies that the story of her life is being written and says that such a biography would be completely unauthorized. Snoopy gives no response but he immediately abandons the biography and starts playing at being the World War I Flying Ace instead.
The author is referred to again in a storyline from October and November 1972, in which her book The Six Bunny Wunnies Freak Out is banned from the school library. Linus writes a letter to Miss Sweetstory, informing her that he is campaigning to get the ban lifted and has hired an attorney to help him.