What are the motifs in The Memory Keeper's Daughter by Kim Edwards?

Protecting Others is a recurring idea in the story. David Henry spends his adult life helping people who are less fortunate, just as he spent his childhood protecting his weaker younger sister. He tries to assist patients who have no insurance, and stays after hours at his clinic in order to see those who cannot afford his services. His biggest mistake in being protective, of course, is protecting his wife from the truth of their baby daughter, which creates havoc throughout his life.