What is normal when it comes to siblings fighting and not getting on? My two are 11 and 6, so an age gap. But, they fight every single day, they absolutely hate each other, my DS is 11 and DD 6. DS is horrible to her and has been for years. Their father said it was something they would grow out of a few years back but, this is too much. I’m honestly debating one moves in with their father full time as it’s damaging for everyone.