I can't stand the fact that my soon to be husbands ex that he had a baby with can't get over the fact that I'm here and…

I can't stand the fact that my soon to be husbands ex that he had a baby with can't get over the fact that I'm here and I'm gonna be here. We have been together for over a year. We don't get to even see his daughter that much because she doesn't like me even though she has moved on a lives with another guy and he says nothing to her about him. Yet I'm pregnant with his her daughters brother but yet she still post stuff like this on Facebook and it Errks my nerves. Idk what to do I'm just tired of it like why can't people be civil and move on.