Who is Great-Grandmother from The Corn Grows Ripe and what is their importance?

Great-Grandmother is also known as Mamich, or little grandmother. She is Tigre's great-grandmother. She is very old and wrinkled. She lives with the family and helps them with chores. She is stern with Tigre. She thinks he is lazy and his parents spoil him. She disagrees with how they let Tigre do whatever he wants while the rest of the family works. Great-Grandmother gives Tigre disapproving looks or makes nasty comments to him. She is the only person who reminds Tigre that he is selfish. She openly voices her opinion that Tigre needs to work and learn how to be a hard worker. Her voice is strong, but his parents still spoil him.