The irony of power and freedom
Donata feels stifled in her home, which is ironic, because she belongs to the most powerful family in Venice. The Daughter does not actually share her father's power, though, because as a royal family, they must keep up with appearances, so actually Donata's life is often devoid of choice or personal freedom. The irony between her royal status and her feelings of powerlessness are evidence of a deep thirst for freedom that defines her personality.
The convent problem
Donata is likely to marry, but her little siblings are actually likely to be sent to a life of abstinence in a convent, according to local tradition. They do not want to be forced into a long life of service and chastity. They want hot boyfriends who can become hot husbands. That is to say, they want to fulfill the natural plot of their lives. Why should a local custom be so antithetical to their human nature? The answer is misogyny and outdated ideas about virginity, which is what the irony points toward.
Life and disobedience
This novel shows Donata scheming with her sister as if they had just discovered sneaking out for the very first time. Donata thinks of the idea and escapes, seeing life from the position of a young peasant boy (she is in disguise). On one hand, she broke the rules. On the other hand, she is fulfilling her natural calling to be curious and investigative. There is an irony in her character on this front, because although she herself probably feels like a rule-breaker, she is actually obeying the urgent call of her own life. By breaking some rules, she ironically upholds others.
The conversion
The whole family is stunned when Donata announces her conversion to Judaism. Well, hopefully her motivations are theologically grounded, right? No. She does not abide by expectation there either. She does this unforeseen and confusing thing for two reasons: Because she can, and for her sisters' benefits. It would be psychologizing to speculate which of those motivations is the primary one, but in any case, the conversion is very striking for its ironic nature.
Donata's authority
As commented before, Donata's character is shaped by authority systems and the strange, creative ways that Donata navigates them. Her authority is ironic in another sense as well. She is a powerful person, but not because she has been given freedom. She is powerful because she felt chronically oppressed. Her authority is firsthand experience gained—ironically—by breaking the rules. Her authority comes from her consistent loyalty to her own point of view and opinion.
