"Ma’s awful partial to you," said Al. "She mourned when you was gone. Done it all to herself. Kinda cryin’ down inside of her throat. We could tell what she was thinkin’ about, though."
– John Steinbeck
The Grapes of Wrath, Chapter 16. Al Joad tells his brother Tom how much he was missed by his mother during his four years in prison. But in typical Ma Joad fashion, she hid her grief over the loss of her son from the rest of the family. This shows how important family is to Ma.