After Dr. Jewett died, a loss Sarah felt keenly, she continued to live with her mother, her older sister Mary, and her younger sister, Carrie, in the Jewett House. Carrie was the only one of the sisters to marry. Following Mrs. Jewett’s death, the sisters inherited the house and redecorated parts of it in the Arts and Crafts style, though they carefully preserved the maroon flocked paper in Mary’s room, which Sarah hated. Eventually Jewett house was given to the SPNEA, today "Historic New England," and today it appears to the visiting public just as it was when the sisters lived there.

Sarah always had close connections with Boston, where she often spent winters. She was first introduced to the Boston literary elite by James T. Fields, raised in Portsmouth. After his death Sarah became an intimate friend of the editor’s widow Annie Fields. In the 1880s and 1890s, Annie and Sarah traveled to England and Europe together. Over the years Sarah Jewett and Annie Fields consolidated their lifelong friendship and mutual support, sharing most everything in what is known as a "Boston marriage."

Sarah continued her writing, publishing short stories and novels almost every year. Her most acclaimed work, The Country of the Pointed Firs appeared in 1896 to great acclaim. Its publication was followed in 1901 with The Tory Lover, a historical novel that begins with a farewell dinner for John Paul Jones at Hamilton House. One must be a fan of Jones, of revolutionary history, the French connection, and of Hamilton House, to appreciate this fanciful tome today. But it was Jewett’s writing that attracted two women to restore the historic Hamilton House that, like Sarah’s home, has been preserved as a museum today.

Jewett’s legacy is secure. In 1901 she was the first woman to receive a doctorate in literature from Bowdoin College. But she has also been criticized because her work neglected to mention the social and industrial changes evident in South Berwick and elsewhere. The Irish immigrant workers who populated the mills and worked as household help appear rarely and only in her late stories.