I have yr 6 twin girls. They can be super close but also really really wind each other up.
Dd2 has a temper and lashes out physically whereas Dd1 is much sneakier and winds her sister up no end with little insidious things (hair pulling, copying what she says, blocking the door etc) but always when we can't see.
How to deal? We have done a lot with dd2 on her temper and she is so much better with everyone except her sister who is her trigger. Dd2 regularly gets told off/punished because it is really visible iyswim - no mistaking her pushing her sister into the bathroom door. But Dd1 is sneaky and does things when we dont see them. Dd2 will tell me and Dd1 gets all wide eyed and innocent and I have no proof.
I spend my life talking to both. My parents left us to sibling scraps as did dhs but we weren't like this. I am worried I'm getting it wrong - Dd2 feels like only she gets told off and Dd1 feels like we are not stopping Dd2. It is also incredibly wearing - I am quite a calm and even person and this constant refereeing is doing my nut in (dh just gets snappy).
Both girls are otherwise genuinely lovely elsewhere with family and friends and as I say can be very close and no one gets between them. Lock down/being in the same bubble/not having any space has obviously really made it worse. Both off to secondary in sept where I suspect they will be quite separate which I am hoping desperately will help.
As I have been typing, Dd1 has just painted dd2s leg with nail varnish but it was an 'accident'. Sigh......