[Newworlds]

So you get the autofamily. At least her daughter is pretty young still so I'll give you some advice from someone who knows. As soon as is feasible (sometime after you are married), start calling your fiance "mom" around your step daughter. After about a week of this, gently talk to her about wanting to be a father figure to her and to help your new baby it would be nice if she called you dad, not to take away from her other dad of course.

This will really strengthen your relationship and bond your family tighter and will in no way diminish her bio father if they still have a relationship.