That Gertrude doesn't need to assess every single moment of every single day against societal standards to ensure her behavior passes muster. She has no need to analyze her words, her walk, her matter, but I do.
-- Belle (chapter 1)

Importance: Belle is just beginning to reveal her situation to the reader, specifically that she is living as if she is white during a time when Blacks face inequality.

A colored girl named Belle Marion Greener would never have been considered for a job with Mr. J.P. Morgan. Only a white girl called Belle da Costa Greene would have that opportunity.”
-- Genevieve (2 )

Importance: Genevieve is reminding Belle of the opportunities she has and why she has to be so careful to guard her secret. While Belle says the reminder is unnecessary, she sometimes struggles to live with the secret, which makes it clear that Genevieve's reminders serve a purpose.

My glance lingers too long, and...
-- Belle (7 )