Hun I'm having the same problem with mine. Problem is Hannah has now started hitting back
so it turns into ww3 if I don't drag one away. It's also getting hard to tell who started it if I'm out of the room for some reason and this is generally when it kicks off.
All I do is just seperate them, I don't even tell either off. The fact that they can't get to each other is punishment enough for both and they tend to calm down and I allow them to play together again but make sure they have a focus like sharing cars on the road mat or building them a den to chase each other in and out of.
Sorry I'm a bit rubbish. Tbf me and my brother continued to beat each other well into our teens (probably early 20's if I'm honest
) but we were always close and played well together the majority of the time
the only time we would start is if we wanted attention so I guess ignoring it is the only thing you really can do
xx