With Stevenson
After Hervey's death, Fanny moved to Grez-sur-Loing, where she met and befriended Robert Louis Stevenson. A 1916 recollection of her by L. Birge Harrison (published in the Centenary Magazine) recalls, "That she was a woman of intellectual attainments is proved by the fact that she was already a magazine writer of recognized ability, and that at the moment when Stevenson first came into her life she was making a living for herself and her two children with her pen." Convinced of his talent, she encouraged and inspired him. He became deeply attached to her, but in August 1878 Fanny returned abruptly to California.
In July 1879, Fanny cabled Stevenson that she planned to leave her husband permanently. Stevenson announced his intention of following her, but his parents refused to pay for it, so he saved to pay his own way. In August 1879, despite protests of family and friends, Stevenson went to Monterey, California, where Fanny was recovering from an emotional breakdown related to indecision about whether to go through with the break from her husband. Stevenson wrote many of his most 'muscular' essays in Monterey while awaiting Fanny's decision.
She ultimately chose Stevenson, divorced Osbourne, and in May 1880 she and Stevenson were married in San Francisco. A few days later, the couple left for a honeymoon in the Napa Valley, where Stevenson produced his work Silverado Squatters. He later wrote The Amateur Emigrant in two parts about his passage to America: From the Clyde to Sandy Hook and Across the Plains. His middle-class friends were shocked by his travel with the lower classes; it was not published in full in his lifetime, and his father bought up most copies.
In August 1880, the family moved to Great Britain, where Fanny helped to patch things up between Robert and his father. Always in search of a climate conducive to Stevenson's ailing health, the couple travelled to the Adirondacks in the US.
In 1888, Fanny Stevenson published a short story, "The Nixie", which William Ernest Henley recognized as based on Katharine de Mattos's idea they had discussed the previous year. He wrote to her husband: "Why there wasn't a double signature is what I've not been able to understand." This accusation of plagiarism led to a bitter quarrel and rupture of the Stevensons with Henley and de Mattos.
In 1888, the Stevensons chartered the Casco out of San Francisco and sailed to Western Samoa. Later voyages on the Equator and Janet Nicoll with Fanny's son Lloyd Osbourne followed. They settled in Upolu, at their home Vailima, where Stevenson died on 3 December 1894.
