How do Walter and Ruth describe their relationship?

Mama's reaction to Walter's questioning where she's been all day illustrates her place as the head of the family.

MAMA: You know better than to question me like a child, Brother.

Mama is the caretaker of the family, which includes Walter.

MAMA (putting her finger on his nose for emphasis): She went out and she bought you a house! (Talking to Travis)

Walter is the spoiled son....

WALTER (bitterly): So that's the peace and comfort you went out and bought for us today!