What does Giovanna realize about Vittoria over the course of the novel, The Lying Life of Adults?

The more Giovanna gets to know her enigmatic aunt, the more she realizes how right her parents were about her. Vittoria's capacity for bitterness seems boundless. Whenever she feels wronged by someone, she retracts her love. Whenever she feels someone's affection, she returns the sentiment. Her character allows the author to explore the ways in which interpersonal alliances have the capacity to rapidly change.