Very few classic eighteenth-century children’s books have an origin myth, or story about how an adult came to write for a real child because the book he or she imagined didn’t exist and later decided the manuscript should be published for others’ enjoyment. The only one I can think of is Mrs. Barbauld’s brief account of Lessons for Children (1788): “Amidst the multitude of books professedly written for children, there is not one adapted to the comprehension of a child from two to three years old …This little publication was made for a particular child [i.e. her nephew and adopted son Charles], but the public is welcome to it.”
The Adventures of the Six Princesses of Babylon (1785) is not in the same league as Lessons for Children, but it stands out because we know the author’s name, how she got her first book in print, and something about her later career. Miss Lucy Peacock described herself modestly as young and not possessed of advantages, but must have been a rather determined person. She had written for young ladies a book-length imitation of Edmund Spenser’s Faerie Queene entitled The Adventures of the Six Princesses of Babylon. It is an original allegory about the passions, not a juvenile abridgment of Spenser, as is usually claimed. Perhaps no bookseller would do business with this unknown writer. Without any prospect of a publisher promoting the book via newspaper advertisements, she decided to try subscription publication instead, which the Oxford Companion to the Book defines as:
A system of obtaining orders (and sometimes payment) in advance to enable publication of a book. Worthy books have often been declined by publishers as poor commercial risks. Financial responsibility for their publication then falls on the author, who generally invites others to share the costs.
Bound into the first editions is a list of subscribers, or the names of people who signed up to reserve copies of The Six Princesses of Babylon. Actually, there are three different versions of the list and the differences between them contribute new information to the story of her campaign. The first one is the shortest, but Peacock’s tactics for garnering subscribers is clear. 
She had success attracting the custom of fashionable, titled ladies: at the head of the Ds is “Her Grace the Duchess of Devonshire,” none other than the showy and notorious Georgiana Spenser Cavendish. A devoted mother after her fashion, Georgiana put down for seven copies. Peacock also signed up a number of celebrated London musicians, the best known being Dr. Charles Burney, father of novelist Fanny Burney, who also took a copy. Then there was the Queen of the Blue-Stockings, Elizabeth Montagu. Philippe-Jacques de Loutherbourg, marine painter, designer of the Eudophusikon, a miniature mechanical theater, the inventor of spectacular stage effects, and his wife both subscribed. Philanthropist, opponent of tea-drinking, and eventual champion of chimney sweets, Jonas Hanway can be found on the list. And Peacock also landed Lady Charlotte Finch, royal governess to the children of George III and his consort Charlotte.
Hopkins, William; Lady Charlotte Finch (1725-1813), Governess to the Children of King George III; Government Art Collection; http://www.artuk.org/artworks/lady-charlotte-finch-17251813-governess-to-the-children-of-king-george-iii-28466
Could Lady Charlotte had something to do with Peacock obtaining permission to dedicate the Six Princesses to nine-year-old Princess Mary, the eleventh child of George and Charlotte, and their fourth daughter? The subscribers’ list was reset with the dedicatee’s name at the head of the names in all caps. Princess Mary’s approbation seems to have swelled the list with enough new names that it had to be reset a third time to fit in another two pages of names.
Coaxing members of the London elite was hardly a novel tactic. What was original about Peacock’s approach was that she solicited subscribers in girls’ schools from the very beginning. There are twenty-two described as such, with the names of the pupil-subscribers set down, giving some indication of the school’s size. 
The appendix of girls’ schools in Nicholas Hans’ New Trends in Education in the Eighteenth Century (1951) does not record any of them. But it is possible that there are more schools there. A few of the heads of school put down for multiple copies but did not give the pupils’ names. Could some of the subscribers who took more than three copies but do not seem to be members of the book trade have been educators? Peacock’s list of subscribers could be a good jumping off point for further research on girls’ education.
Who was this enterprising young lady who signed the end of every copy? Her exact identity has yet to be established from perusing Ancestry Library can be trusted. We do know that she continued to write for young people—original works, including several featuring Black and Creole characters, translations from the French, and reference works. She also took charge of their sale and marketing from her Juvenile Library on Oxford Street. She edited The Juvenile Magazine (1788) for John Marshall. Did a male relative or friend help her get started on her interesting career in the literary world? That is yet to be determined, but perhaps a strong entrepreneurial streak surfaced as early as her drive to write.