@Theydontwantme that sounds really really hard.
Ive never had that level of intensity with dc2. But I learnt very quickly that punishing him was the worst thing I could do. So I didn’t (I didn’t punish dc1 either). Just told dc2 No if he was hitting his sibling first example and took him to a different room. Then wait for him to calm down.
My understanding of polyvagal theory is that, in a case like this, you might want to intervene, go Somewhere a bit quieter if you can and just stay with dc. No talking but being calm (co regulation) and using techniques yourself to calm down (concentrating in breath, fiddle toy etc….) so dc has an example of what to do themselves.
It might also be your dd would benefit from someone else teaching her ‘calming methods’ like breathing, counting, etc simply because she is getting closer to teenagehood and children/teenagers don’t take parents advice well 😁😁. We are and always be wrong.
Its not an easy one to crack really because, imo, ‘standard’ parenting advice doesn’t work.