1839–57: Death of Sarah Buxton, abolition work, European travels and scholarship
Sarah-Maria Buxton died in 1839. As a result of her own insistence, Gurney authored and spoke a funeral oration, led her funeral service, and wrote her a poem for her gravestone. Gurney continued to inhabit the cottage for the remainder of her life; she from this time was referred to as "Anna Gurney of Northrepps Cottage".
In 1840, The Remedy, a sequel to The African Slave Trade (1839), was published. While it is credited to Thomas Fowell Buxton and he composed its initial draft, and Priscilla Buxton did most of the work, Sarah Buxton and Anna Gurney had had close involvement.
Gurney worked with Amelia Opie, a close family friend of the Gurneys and Buxtons, to create a ladies' anti-slavery society in Norwich. Opie was known to refer to Anna Gurney as 'Dr Gurney'.
In 1841 in Archaeologia, the journal of the Society of Antiquaries, is a communication from her on The Discovery of a Gold Ornament near Mundesley in Norfolk, and a paper On the Lost City of Vineta, a submerged Phœnician city, as well as a third publication. All three are totally anonymous; they were credited to a "gentleman unnamed" when read out by George Ellis. As vice-president of the Society of Antiquaries in charge of publications, Hudson Gurney likely helped arrange publication for these pieces; these were letters sent to Sir Henry Ellis, the Principal Librarian of the British Museum, to whom she was a friend, as well as a consultant. However, there is no evidence that she used the British Museum's Reading Room. Gurney also learned a number of African languages, and wrote a grammar on the Hausa language, alongside the Reverend James Schön. Schön, a missionary, had previously been on the 1841 Niger expedition and African Baptist Augustus William Hanson, who had learned from Gurney's own philosophy of language, had taught Schön the language Accra. Gurney and Schön also translated the Bible into Accra. In addition to this, Samuel Ajayi Crowther, a former slave with whom Gurney worked, visited her around this time and additionally preached at the church in Overstrand.
Alongside the Buxtons after her partner's death, Gurney visited Rome, Athens and Argos, and was contemplating a voyage to the Baltics. When they were in Rome, a paper that she had authored by Gurney, arguing for a less cruel method of animal slaughter, was presented to the Pope and was successful. In 1845, she became an associate of the British Archaeological Association, being the first woman to join the association as a member. In 1847, she also became the first woman to be elected a member of the Philological Society. That year, she appears as a listed annual subscriber to the London Library in its second catalogue; she obtained these books through the General Post Office. In 1848, she presented a copy of her Literal Translation to the Philological Society.
Gurney appears to have contemplated publishing a revised A Literal Translation, which would have contained Norse and Welsh sections for comparison, before deciding against this. It seems as though she allowed John Allen Giles to use a significant amount of her work; this highly derivative version of the Anna's Chronicle translation was published in 1847. M. J. Toswell has argued that she would have regretted allowing this use as Giles patronised her in the acknowledgement and made scant revisions, choosing not to credit her as a translator on the title page.
In March 1850, Gurney embarked on a scholarly search for the life of Saint Edmund, becoming particularly interested in his martyring by the Vikings. This search continued at least into April, when she wrote a poem about her search:
She had her own copy of the Iolo Manuscripts from 1850 after borrowing a copy the previous year, published a letter in her own name in Archaeologia in 1852, and produced an article on Norfolk Words in 1855, which was read at a Philological Society meeting.
In her later life, she studied Danish, Swedish, and Russian literature. In 1854 it was confirmed to her that her brother Richard had made Hudson Gurney his heir rather than her; she wrote that he told her, "I do not approve of women having large responsibilities", and that she "honestly acquiesced & concurred with him" as she feared that she would not be able to live up to the responsibilities that came with expanded finances. In 1856, George Borrow visited Gurney at the cottage, after stating that Gurney was one of three people in the world that he had always wanted to meet, the others being Daniel O'Connell and the derby winner Phosphorus, both of whom had died. Upon that visit, Borrow wrote that Gurney asked him to explain a difficult point in Arabic before talking over his explanation. He wrote, "I could not study the Arabic grammar and listen to her at the same time, so I threw down the book and ran out of the room." He allegedly continued running until he reached Old Tucker's Hotel at Cromer before travelling on to Sheringham.
10 days prior to Anna Gurney's death, she made a suggestion to the BAA that they should begin to publish short reports on worldwide archaeological discoveries. She offered to oversee such reports on northern antiquities. She had been developing "a compilation of derivations from the Hebrew into Greek, English, and German, to show the common origin of languages" at the time of her death. She was also making a plan for a significant restoration of the local church which would have included an extension to the building.