Elizabeth could not see Lady Catherine without recollecting that, had she chosen it, she might by this time have been presented to her as her future niece; nor could she think, without a smile, of what her ladyship’s indignation would have been. "What would she have said? how would she have behaved?" were questions with which she amused herself.
– Jane Austen
Pride and Prejudice, Chapter 37. Elizabeth entertains herself at Lady Catherine’s expense. Each time Elizabeth looks at her she smiles at the thought that had she accepted Darcy’s proposal, she would have been presented as a future niece to the indignant Lady Catherine!