They REALLY need to add a step-parent relationship...
So I know they show up in the family tree. But ingame your stepparent is just a roommate living in the same house as you. There is no special relationship flag. And when the kids Age up they can da...
We need to keep asking for this until someone pays attention. I have a step-daughter in RL, so it bothers me that I cannot replicate that relationship in my game - especially as I could do it in Sims 3.