I'm thinking of giving my 12 year old daughter her own room but making my son share a bed room with his half sister. I think you have an opinion this too, right?
Uh, my opinion? You actually want it? Why can't they all have different rooms?
Because I want my children to have different treatment in upbringing.
You are a horrible parent for not wanting the best for them all. All of your children deserve separate rooms, and you can't put your biological daughter over everyone else. It's unfair, favoritism, and will breed resentment from the ones that aren't treated as well as her.
I know. I want my children to all fight and hate each other because then they will become stronger from it.
You are making this harder for your family by not doing the right things. This is toxic and they will have mental issues. Get mental help, something is wrong with your thinking.