She did write a preface to the second edition of "Jane Eyre" in 1848, but this was not written by her. It was written by William Makepeace Thackeray, a prominent author of the time, and published anonymously.
Thackeray's preface was meant to defend the book from criticism and highlight its literary merit. He praised Brontë's writing style, her ability to create believable characters, and the novel's exploration of social issues.
While Charlotte Brontë did not write a preface herself, she did write letters to her publisher expressing her thoughts on how to market her books. She was aware of the need to appeal to a wider audience and wanted to ensure that her novels were received favorably by readers.