Margaret Starbird is the author of four books on the underground Christian tradition that held that Jesus was married to Mary Magdelene. Her works along with those of Lynn Picknett, Michael Baigent and others were highly influential upon Dan Brown's The DaVinci Code and are directly mentioned in that work.
In her 1993 book The Woman with the Alabaster Jar: Mary Magdalen and the Holy Grail, Margaret Starbird developed the hypothesis that Saint Sarah was the daughter of Jesus and Mary Magdalene and that this was the source of the legend associated with the cult at Saintes-Maries-de-la-Mer. She also claimed that the name "Sarah" meant "Princess" in Hebrew, thus making her the forgotten child of the "sang réal", the blood royal of the King of the Jews.
Her works contain many references to ancient numerology (known as gematria) and classical art. Starbird believes that the official Catholic church suppressed the veneration and devotion of the sacred feminine, leading to a unbalanced spirituality in mainstream Christianity.
She is the mother of Stanford basketball star Kate Starbird.