I feel that some step mothers or potential step mothers have some kind of automatic disgust for their step children, no matter what they look like. I can't count how many posts I've read in a Swedish parenting forum about how they feel their step child is "nasty" or "yucky", they don't want to touch them, they stink etc etc. It's probably some remnant of an instinct to only protect and love our own offspring.
Regardless, I feel that she is doing him and his children a disservice by continuing this relationship. Besides, they have four kids between them, why would they need more?
It's better for her to find someone without children. That's what I would do if I ever broke up with SO. I don't want to deal with step children or ex-wives/girlfriends.
Yes. This is what I wanted to say. Some stepmothers may feel the children of their current spouse/SO will always remind her of the woman he once had. Many dont like that.
Another thing, all children go through stages but good parenting to me is seeing the best in your children through these stages.