do something (anything) for other people, like everyone else has for her.

Well, she did put up with entertaining Fabric Lady for Liang's sake :P But yeah, she is not much on giving, is she?

Btw, I don't know if you noticed, but the Fabric Lady is the same actress who played Qing Mei in Mars and plays Wei Yi's fiancee in Silence. She seems to have made a career of losing hunky men to other women.

Does evil dad keep her in a box and only bring her out if he wants to totally crush Sui?

Seriously. And why does Sui never think about it, at all?