Hello bitt: I see this is your first post here on PC. So... welcome to PsychCentral! I hope you find PC to be of benefit.

I don't know as I have the answer to your question. Perhaps there is a difference between thinking about divorce versus actually watching it happen. There's also a scientific theory I've read about on a couple of different occasions recently that might be applicable here. It's called the "sunk cost effect". Basically, as I understand it, what it says is that we humans (& some other species too) hate to give up on something we've put time into even once it has become completely apparent it's a lost cause, so to speak.

For one thing, we don't want to admit we may have been wrong to begin with. Plus we abhor the idea of giving up on something we've already put so much time & effort into. How we tend to act in relationships is said to be a prime example of the sunk cost theory. So perhaps it's just difficult for this lady to actually let go of her marriage (as opposed to just thinking & talking about it) because she has so much invested in it, in spite of the fact that the husband is abusive.

Anyway... those are just a couple of different ideas that occur to me on the subject. Ultimately the only person who really knows is the lady in question.