Potter continued to write stories and to draw, although mostly for her own pleasure. In 1922, Cecily Parsley's Nursery Rhymes, a collection of traditional English nursery rhymes, was published. Her books in the late 1920s included the semi-autobiographical The Fairy Caravan, a fanciful tale set in her beloved Troutbeck fells. It was published only in the US during Potter's lifetime, and not until 1952 in the UK. Sister Anne, Potter's version of the story of Bluebeard, was written for her American readers, but illustrated by Katharine Sturges. A final folktale, Wag by Wall, was published posthumously by The Horn Book Magazine in 1944. Potter was a generous patron of the Girl Guides, whose troops she allowed to make their summer encampments on her land, and whose company she enjoyed as an older woman.[84]
Potter and William Heelis enjoyed a happy marriage of thirty years, continuing their farming and preservation efforts throughout the hard days of World War II. Although they were childless, Potter played an important role in William's large family, particularly enjoying her relationship with several nieces whom she helped educate, and giving comfort and aid to her husband's brothers and sisters.[85]
Potter died of complications from pneumonia and heart disease on 22 December 1943 at Castle Cottage, and her remains were cremated at Carleton Crematorium, Blackpool. She left nearly all her property to the National Trust, including over 4,000 acres (16 km2) of land, sixteen farms, cottages and herds of cattle and Herdwick sheep. Hers was the largest gift at that time to the National Trust, and it enabled the preservation of the land now included in the Lake District National Park and the continuation of fell farming. The central office of the National Trust in Swindon was named "Heelis" in 2005 in her memory. William Heelis continued his stewardship of their properties and of her literary and artistic work for the twenty months he survived her. When he died in August 1945, he left the remainder to the National Trust.[86]
