I think I'm going to compare my sister-in-law to isis
Do you really feel she acts that bad?
She is because she's worse than the terrorist group which isis
Family can be difficult but insulting her by comparing her to a terrorist group is not good. It will not make the relationship better and will make things worse.
I'm going to get fired for this.
It is rude to talk about your family this way. Isis is horrible and they kill innocent people, it is unfair to claim your sister is doing the same.