I have two kids DD 4.5 and DS 2.5. Like all sibs they fight. Sometimes a lot.
Generally they do get on and can play for hours together and can be very affectionate. However, DS is a typical boy and can be very physical. Sometimes this is just over enthusiastic affection but often its a typical toddler lash out when his sister won't do what he wants. Most mornings there is some squabble or another and often one or both ends up in tears.
Sometimes I rush in and police their fights but other times (like this morning) I wonder if its just better to let them get on with it and sort it out themselves?
Do you let them get on with it? Or constantly try and intervene and referee?