Frances' concern was existential; she lately had found herself mired in an eerie feeling, as one standing with her back to the ocean.
-- Frances (chapter 1)

Importance: As Malcolm and Frances return home from the party in Chapter 1, they are both distracted by their own deep thoughts and feelings. While Malcolm worries about Susan being angry with him, Frances feels an existential malaise she cannot quite identify. In this quote, the author is establishing a premise that will be important later. Even before Frances learns about the loss of her money, she is feeling depressed, therefore her ultimate suicide cannot be attributed to this fact alone.

Sometimes the world corrected itself, she knew this, for it had so many times in her past. She understood intuitively that it would not correct itself now, though."
-- Frances (chapter 2)

Importance: This quote further establishes Frances' depression. It seems as though she has a presentiment that bad things are coming, which...