Author J.K. Rowling exits Manhattan federal court, Monday, April 14, 2008, in New York after testifying on the first day of her trial against a publishing company. [Agencies]

J.K. Rowling says the Harry Potter characters she created are as dear as her children, too precious to allow an inferior Potter encyclopedia to be published without letting the world know the ordeal is draining her of her will to write.

"I really don't want to cry because I'm British, you know," the mother of three told a judge Monday in U.S. District Court as she described how much her characters and seven books mean to her. "You know, these books, they saved me, not just in the very obvious material sense, although they did do that. ... I would have to say that there was a time when they saved my sanity."

Last year, Rowling sued Michigan-based RDR Books to stop publication of Steven Vander Ark's "Harry Potter Lexicon," claiming copyright infringement. Vander Ark runs the popular Harry Potter Lexicon Web site, and RDR wants to publish a print version of the site and charge $24.95.

RDR publisher Roger Rapoport, who testified in the case Monday, was to return to the witness stand Tuesday.

Rowling claims the lexicon is nothing more than a rearrangement of her material, and she told the judge it copied so much of her work that it amounted to plagiarism. She said she was "extremely shocked" because Vander Ark had said on his site he would not publish a book.

"I did feel a degree of betrayal," said Rowling, who lives in Edinburgh, Scotland, with her husband and children. "I believe that it is sloppy, lazy and that it takes my work wholesale, verbatim. This book constitutes wholesale theft of 17 years of my hard work."