@ancientgran I am not going to ever condone shouting and swearing from anyone.
We'll just have to differ that someone who does this, is fair game to be assaulted.
In my home with 4 children in an around that age, that definitely can irritate each other at times, violence would never be tolerated.
It really is that simple in my home.
If one of my son's assaulted my daughters because she was shouting and swearing at him, I would not accept being told it was sorted, refusing to answer questions and then allow him to give me a version days later that excused his behaviour in HIS eyes only, all the while as he continues to live in our home.
There is no excuse for violence.
I appreciate many posters believe there are acceptable circumstances, and the sister shouting and swearing is one of those circumstances.
It isn't for me, nor will it ever be, and certainly not in my home.
I appreciate that that can be very difficult for some people to grasp.
In some homes, violence doesn't ever happen and would never be tolerated.
My children have never hurt each other deliberately.
They have annoyed, irritated, called each other names and teased each other on occasion, as children, but they have never laid a hand on each other, even the boys.
If they had, it would have been dealt with very firmly, so that they would known it was completely unacceptable at a young age.
As adult young men now, they have never had a physical fight with any of their large circles of friends and I have never heard of any of their friends ever being involved with a physical altercation either.
Lots of men live long lives without raising a hand to anyone, much less their sister.