Without warning Grampa being to cry. His chin wavered and his old lips tightened over his mouth and he sobbed hoarsely. Ma rushed over to him and put her arms around him. She lifted him to his feet, her broad back straining, and she half lifted, half helped him into the tent.
– John Steinbeck
The Grapes of Wrath, Chapter 13. Ma Joad is the emotional and physical backbone of the Joad family. When Grampa, who is about to die and likely knows it, breaks into sobs, Ma is the first to rush to him and offer comfort and support. The Joads look to Ma for their strength and hope.