Reading the Promessi Sposi's IX chapter you can see that the Monza's nun isn't a common nun.

Firt of all the writer himself tells you that explicily by using the words " la signora è una monaca: ma no è una monaca come tutte le altre"and then he specifies that she isn't different because she is an abbess or a prioress but because of something else.

Immediately at the beginning of the narration she shows herself mysterious and cryptic: the main characters look for her a lot before they meet her and she appears behind bars so she is always distant as if she was shrouded in a veil of mystery that hides her. Another ambiguity is between her social status: Manzoni describes her like a nun but also a lady.

When the writer starts to describe her he frequently uses words like "seems" and "look like" to express the differences between her appearance and how she is really. Moreover he uses three essential Adjectives: "sbattuta", "sfiorita" and "sconcertante". The first two suggest the idea of an harassed and old woman, and the third one best express the concept on the thesis: she was out of the ordinary, different from the others, "out of tune" ( indeed both expressions belong to the semantic field of sound).

Also her clothing are used to express the concept of her ambiguity. The contrast between veil black and veil white and the extreme attention to detail but the hair coming out of the veil suggest her ribellion and the two parts of her soul: the pure and neat one and the mysterious and disquieting one.

The writer makes a long and accurate description of her different expressions and glanades . These underline different aspect of the nun's soul: at moments she asks affection and pity, in others she looks down as if she had guilt and sometimes she expresses repressed hatred. She isn't easy to interpret.

In addiction Manzoni chooses words with screeching sounds that make the description even more expressive and suggest the disquieting atmosphere.

For the reasons that I express previously I think the Monza's nun isn't a predicted and bored character and she isn't a common nun.