My Child Sims Won't Stop Being Mean!!!

SO Remilia and Flandre Scarlet from Touhou Project are sisters, and I added the scarlet devil mansion to sims 4 a couple months ago and they will not stop being mean. I have to constantly "Apologize" and because of Remilia's charisma skill, "Smooth Apology" each other. They're children AND Remilia has the evil trait. Is there any mod to help me? Or anything? I used cheats to made them best friends forever, but their friendship level quickly WENT TO LIKE 16 and so I BFFed them, again

Edit By Crinrict: Removed all-caps from title