However, there were problems between Thrale and Johnson, along with "his defenders" during his life and in criticism since then, over their "gradual estrangement" from each other after the death of her husband. These problems were then heightened by her marriage to Gabriel Piozzo. After Johnson's death, Thrale felt isolated and thought that Johnson's previous friends or the public as a whole did not accept her, and some went so far as to claim she abandoned Johnson in his final moments. In particular, James Boswell, who resented Thrale and felt himself as her literary competitor, began to exploit the falling out between Thrale and Johnson's friends in order to promote his Life of Samuel Johnson.
After the birth of Queeny, Thrale began to document the various moments in her daughter's life in a "baby book" called The Children's Book. The work eventually expanded to include documentation of the whole family and was retitled the Family Book. To encourage his wife's writing her husband Henry Thrale gave her six blank diary books, with the title Thraliana on the cover, in 1776. The work was intended as an Ana, which she admits her fascination with in the Thraliana: "I am grown quite mad after these French Anas; Anecdote is in itself so seducing". She searched for English models and was only to find Selden's Table Talk, Camden's Remains, and Spence's Anecdotes. In May 1778, she was given by Johnson a manuscript of Spence's Anecdotes, but her first years of the Ana were written without an exact model.
Before the Thraliana, Thrale kept two sets of anecdotes: the first was devoted to Samuel Johnson and the other for miscellaneous events. She relied on these, along with her memory, to write the early portions of her work. Boswell, when trying to find information for his own work, wrote:
"Mr. Thrale told me, I am not sure what day, that there is a Book of Johnsoniana kept int heir Family, in which all Mr. Johnson's sayings and all that they can collect about him is put down ... I must try to get this Thralian Miscellany, to assist me in writing Mr. Johnson's Life, if Mrs. Thrale does not intend to do it herself.After Johnson's death, Thrale used the Thraliana to create the Anecdotes of the Late Samuel Johnson (1786). However, the Thraliana itself was not published until 1942, where it was produced by the Clarendon Press in England while its editor, Katharine Balderston, was prohibited from traveling across the ocean from Wellesley College because of World War 2. Until 1940, the manuscript was owned by A. Edward Newton until his death in fall 1940.
"It is many Years since Doctor Samuel Johnson advised me to get a little Book, and write in it all the little Anecdotes which might come to my Knowledge, all the Observatiosn I might make or hear; all the Verses never likely to be published, and in fine ev'ry thing which struck me at the Time. Mr Thrale has now treated me with a Repository, - and provided it with the pompous Title of Thraliana; I must endeavour to fill it with Nonsense new and old.These encouraging remarks from Johnson set the theme of the work as it became a new "Johnsoniana" collection. In particular, she transfered her previous notes and documentations about Johnson's life into the collection.
In a 6 September 1777 letter, Johnson told Thrale to be "punctual in annexing the dates. Chronology you know is the eye of history". However, the system of Ana allowed Thrale to group items by theme instead of by topics, like "Odd medical Stories", to organize anecdotes, quotations, and stories. When Henry Thrale died while Thrale was writing Volume Three, the work became a diary for Thrale to discuss her thoughts and feelings after her loss. This volume soon began to describe Thrale's feelings for Gabriel Piozzi. Throughout the Thraliana, Thrale examines how others view her, which reveals her anxieties that she had about how she was perceived. This is especially true when she writes: "Life has been to me nothing but a perpetual Canvass carried on in all parts of the World - not to make Friends neither - for I have certainly found very few - but to keep off Enemies". Thrale initially did not want to write in the sixth volume of the Thraliana, but did so because "Johnson said that Pleasure might one day be made from such Nonsense, so I'll e'en finish this last Volume of Anecdote & store up no more Stuff". However, she did not stop journal writing after she finished like she claimed, but instead continued on writing for the rest of her life.