Your milieu is not the same as your sister’s. It is an ever-shifting, individual configuration of information flows. The Twitter feed you have curated is a milieu. Your friend group (which is not the same as the friend groups of the other people in that group!) is a milieu.
It is by changing your milieu that you change yourself.
convinced that adults have totally forgotten how to have fun in conversation. every conversation is either "checklist catch up on life events" or "grave discussion of public events we must feel sad about". we've totally lost the sense of play. hold your beliefs loosely, laugh.
In other words, siblings are forced together, and then suddenly they’re not. The independence of adulthood—when proximity is no longer required and the obligations lessen—creates opportunities for siblings to build, repair, or discard the relationships of their youth, to stay stuck in or break free of the roles they played as children.