How does the character Ivy Rowe impact the book Fair and Tender Ladies?

Lee Smith's novel Fair and Tender Ladies is epistolary, meaning that it is comprised entirely of letters. The novel's letters are written by the fictional character and protagonist Ivy Rowe. They are addressed to various recipients over the course of Ivy's life from childhood to old age. The reader experiences the novel's story through the letters, and these letters shape the narrative. Ivy's life is the subject of the letters, and so as a character, Ivy is both the narrator and the subject of her own story. Smith creates this double role for Ivy, which cultivates complexity and depth in Ivy's development as a character.
In Fair and Tender Ladies, we read Ivy's first person account of events in her life. The letters span seven decades, and Ivy's language abilities change over the course of the novel to reflect that. Her Appalachian localisms, her youthful misspellings, and her perspective on the harsh realities of rural life mature as Ivy grows older. To say that Ivy has an impact on the novel is an understatement: she is the narrator and the central character of the novel. It's also important to note that Fair and Tender Ladies consists of letters written only by Ivy. We never see letters that were received by Ivy, although presumably there were responses to many of her letters. This one-sided format ensures that Ivy is truly the centerpiece of the novel and the main character we are interested in as readers.
 
There are many ways Ivy impacts and shapes the novel. She dictates the pace of the stories told in her letters. She is the main character whose story and perspectives are shared. She chooses the details she wants to disclose and the details she wants to keep hidden. Of course, Lee Smith is truly the one making all these decisions, but she chooses to make them through Ivy Rowe, thus giving Ivy agency and full control over the development of the story.