Curiosity kills the cat, says Wilma, don’t make yourself stupid like the one-armed sister.”
-- Wilma (Prologue)

Importance: This quote foreshadows the tragic turn Lala's life takes when she lets herself get carried away by curiosity. This curiosity stems from the rigid structure imposed on her by Wilma. When Lala strays from Wilma's ideals by befriending Tone and then getting pregnant by Adan, she becomes "stupid like the one-armed sister" for disregarding her guardian's wishes (7). This so-called stupidity beings about her a great deal of grief and suffering, as it results in an abusive marriage and the death of her child.

But you cannot call his name, cannot make him stop because, like the wave that crests and falls and disappears somewhere beneath the wooden floorboards, he is out of reach. Somehow beyond you, woman or not.
-- Narrator (Chapter 4)

Importance: How the One-Armed Sister Sweeps Her House focuses heavily on gender roles. Throughout Chapter 4, Lala wonders...