I am past my wits end.
DS1 is 9. DD1 is 7. They genuinely cannot be in the same room together for more than 5 seconds without one or other screaming/hitting the other.
DS1 is very bright (HLP/gifted) - he is happy to be quiet and when he wants to talk/ask questions they have a point and a reason. Theories are thought out/have logic
DD1 is averagely clever (normal for her age) - she loves to talk/sing/hum generally make noise. she talks and sings for the pure fun of hearing her own voice. she will ask stupid/obvious questions in a clumsy attempt to get a conversation going, she speaks before thinking through what she says.
They have been quite reactive to each other since DD1 was around 4 but the last year to 18 months has escalated into something else. They both now assume the other is deliberately trying to annoy them and react as such. Examples:
So DD1 singing will promote DS1 to scream at her to shut up - but its 6 of one half a dozen of the other whether she was singing for fun or to wind him up.
DS1 will decide he needs to get his shoes out at the exact same moment as DD1 is looking for her's in the shoe box. She holds her ground so he screams and shoves her out of the way and she gets hurt. Either could have waited or moved slightly to the side so both could look in the box.
Generally DS1 is always watching what DD1 is doing, looking for something to tell tales about, just waiting for an excuse to kick off. DD1 will quite often deliberately come and start singing/imaginative playing right next to where DS1 is and under the guise of her toys coversation in her games will try and wind DS1 up.
They are absolutely both to blame as much as each other in different ways.
When either one isnt there we have nothing more than the usual sibling upsets with my other 2 (younger) DC. DS1 and DD1 on their own are a delight and lots of fun and very happy.
They have their own rooms so try and encorage them to play there so the other cant annoy them but they dont want to/refuse/have a major tantrum as they feel they are in trouble when it's the other one's fault.
Please someone give me some advice to break their habit of over-reacting to each other! I cant see how to stop this cycle. 