Im not sure what you're asking here. Are you asking from a hijab POV or non-hijab POV? If you wear hijab then obviously will wear it in front of non-mehram like FIL, BIL, cousins, etc. But not your father or brother or at home with your husband.
But if your asking from a non-hijab POV, then just wearing a dupatta across your chest is fine. Why would you cover your head in front of your BIL, FIL, cousins, etc if you dont wear hijab?
Im talking about a non-hijab POV. In a family envoirment.