Siblings can be playing beautifully one minute and fighting over the exact same blue block the next. The goal is not a perfectly peaceful house. It is fewer hurtful fights, less parental refereeing, and children who learn what to do after a conflict.
Separate safety from fairness
Step in quickly for hitting, biting, throwing or a child who is frightened. Use a calm line: "I will not let you hurt each other." Separate bodies first; investigate later.
For ordinary arguments, resist deciding who is right every time. Say, "You both want it. What are your two ideas?" Young children may need choices: timer, trade, another toy, or help finding a solution. They learn more from practising than from a verdict.
Do not make comparisons
"Why can't you be more like your sister?" gives both children a role they did not ask for. Describe the behaviour instead: "The blocks need to stay on the floor," or "You wanted a turn and grabbed. Try asking."
Give each child some time where they are not sharing you. Ten minutes of undivided attention can matter more than an elaborate family outing. It reduces the need to win attention through conflict.
Repair is the useful part
After everyone is calm, help them name what happened and make it right. An apology can be words, fetching ice, rebuilding a tower, or giving space. Do not force a hug. Consent matters even between siblings.
If fighting becomes relentless, this guide to daily sibling fighting has more practical scripts. If one child is being repeatedly targeted, humiliated or afraid, it is not ordinary rivalry; read how to tell sibling rivalry from bullying and get support.