duty to society........that is probably a critical theme in both texts
Austen values a more integrated societal structure, and once Emma recognizes this, stops insulting lower classes and the yeomanry, and embraces them, that is her duty to society which Austen thinks everyone should do
Cher's duty to society is more obvious. helping with the "pismo beach relief", and like Emma, recognizing other people rather than focusing on herself, such as realising that Travis is so talented, is her duty to society
but in my opinion, duty is quite difficult to pull off. you should just go for values such as relationships/mariage or tolerance or education