Responses
Well, when you have a parent who is abusive, your definition of caring gets messed up, lol. No one seemed surprised that the father slapped the MC. We could already see the brother was twisted from the interaction between him and the former Butler. Also the older sister knew of the mistreatment but also didn't say anything.
If the brother has a good relationship with Lilian why would he let her be mistreated for YEARS? But as soon as Leilan finds out he wants to do something, when all of it could've been avoided if he just stepped in beforehand.