Symbolism, Imagery, Allegory
We Believe in Miracles
A few times throughout the book, Brian and Sara talk about miracles. As a paramedic, Brian once retrieved a man who had been frozen solid outside in the snow, only to completely thaw out and reawaken, prompting Brian to observe that "miracles happen" (4.1.51). Sure sounds like he saw one with his own eyes.
Later, Kate wins a goldfish at a carnival, which Sara ends up knocking out of the bowl and almost killing. She manages to fish him out (ha) from under the stove and put him back in the water, but he doesn't move. Just as Kate walks in, "At that moment the goldfish shudders sideways, dives, and starts to swim again. 'There,' I say. 'He's fine'" (4.3.88). Phew.
As if this incident weren't traumatizing enough for the poor fish, though, Sara almost kills it again when she changes its water with tap water. But it lives, again, and Sara looks at Kate and "wonder[s] if I have used up my miracle" (4.3.160). Sara thinks that miracles are finite, and she kind of blames herself for Kate's illness, as though by taking all the good in her life for granted she somehow gave Kate cancer. And Kate's situation is so desperate, it's no wonder that her parents hope for a miracle to step in where science has not.
But if a miracle is something unexpected that happens that saves a life, could Anna's death be seen as a morbid miracle? It ends up delivering that kidney that keeps Kate going, after all, and so while it's gruesome, it's still kind of miraculous.