My son has only been a sibling 1/3 of his life, while my daughter was born being a sibling. My son is still getting the hang of such a responsibility, and lifelong position, while my daughter has it down pat. She knows if your sibling is being quiet and minding their own business, you should always go up and bother them. Whether, its poking them when they aren't looking, getting in their face and talking to them, quiet behavior should always be interrupted. She always knows siblings must share anything especially when it comes to mom's attention, whether its that chair you are sitting on, or the bag of candy you are eating. It has to be shared. My daughter is a pro at annoying her brother when no one is watching and then acting innocent. She also know she would rather crying from what her brother did, instead of playing alone. (Today he took a toy away from her that made her cry, when I sent him away for time out she cried out after him, and wouldn't stop crying until she got to interrupt his alone time by hugging him.) But tonight she topped the cake in sibling rules. Every sibling knows, that no one messes with your sibling, except you.
Tonight I made Turkey Homemade Noodle Soup. The kids were not so excited about a meal, because it doesn't look like it came out of a Campbell's soup can. My daughter never did touch it, without crying, every time we tried to convince my son to take a bite, my daughter would shake her head no, and cry out in defensive of her brother. She did not want him to suffer a fate of eating the terrible homemade mess. My son finally ate some soup in exchange for a bowl of jello. But every bite of his was accompanied with a scream from his sister. She couldn't believe we were being so mean to him. Once he started eating it, he liked it, but my daughter was never convinced and never stopped crying and looking at her parents like we had betrayed the coolest person in the world, her big brother.