The novel Da Vinci Code is remarkably ingenious. I have read it and enjoyed a lot. It is a fiction and evidences for Jesus having a daughter are not very convincing. There are other arguments, however, suggesting that Jesus might have married before becoming a wandering rabbi. It is because the status of a Jewish rabbi comes from his marital status itself. In other words, if you have not married, you cannot become a rabbi simply because nobody trust you. Although The Da Vinci Code is a fiction, it brings out a truth about the Bible and the religion Christianity---biblical writers and early Church fathers suppressed some history and created some others to embellish Jesus in order to build up his divinity, so much so that he eventually became God! So I would say the core message of The Da Vinci Code is true---Christianity is built, at least partially, on lies.