Unbeknownst to Matthew or me, the Bishops and the de Clermonts had been working for years, even centuries, to bring us safely together: Philippe, Gallowglass, my father, Emily, my mother.”
-- Diana (chapter 3)

Importance: Diana has just discovered that Gallowglass watched over her during most of her life, in keeping with the promise he made to Philippe to do so. Gallowglass reveals that he had shown himself to Stephen just before Stephen and Rebecca were killed, meaning Diana's parents knew he was watching over her. She already knew Philippe had made various arrangements to ensure the situation resolved as it was supposed to.

Phoebe sounded as though she were contemplating minor plastic surgery or a change of hairstyle, rather than a complete biological transformation.”
-- Diana (chapter 6)

Importance: Marcus has just announced that Phoebe is going to become a vampire before they marry. Diana is amazed at Phoebe's complacent attitude about this drastic decision and Matthew forbids it...