Maria Edgeworth 
Belinda [EPUB ebook] 

Being unwed, Belinda is sent to live with Lady Delacour, whom Belinda considers fascinating and charming. Lady Delacour believes herself to be dying of breast cancer. She hides her emotional distress from Belinda through wit and charm. The first half of the novel is concerned with the blooming friendship between Belinda and Lady Delacour, which is eventually broken, I see…that she [Belinda] who I thought had the noblest of souls has the meanest! I see that she is incapable of feeling.