Who is Ruth Allston from All the Little Live Things and what is their importance?

Joe Allston's wife, Ruth, is described as a gentle woman who leads with her heart before her head. Ruth's adoration for her son, Curtis, is obvious. As a mother, she often tooks Curtis' side in disagreements with his father. Ruth and Joe have relocated to the California countryside in order to deal with the loss of Curtis, who was their only son.