Here are some things not to do to your sister(s). Some are from experience.
No direct eye contact. She might take this the wrong way and think you re challenging her.
Don't drop concrete blocks on their fingers. That happened ON ACCIDENT!!!! Her fingers were in the way. Turned her into a squeak box.
Don't slap her. She will slap back....... Harder.
Don't spray them with squirt guns. They will spray back...... Or tell mom.
Don't turn your back on them. It might end in disastrous pain.
Don't bother them while they are reading.
Follow this chart and you will have a happy life with your sister(s).
Or you can do what I do and defy everything and make each day a fight for survival. Survival of the fittest, and whoever has on the thickest shirt.