I have a sneaking suspicion that this victim of kidnapping was made to be involved in the sick freak’s crimes to survive and that these crimes lay at the root of the guilt she feels.
Family members say she feels guilty for not escaping from him but I think it is probably more than that.
Once she had children, she wouldn’t have left without them.
Then you make the victim totally dependent on you for every normal purpose ~ eating, drinking, going to the toilet, bathing, dressing, etc.
This gradually induces a feeling of dependency backed up by a powerful feeling of depression.
It can take as little as a month ~ we call that Stockholm Syndrome. It may take 6 months to a year ~ and if it takes longer you send the victim down the line to a tougher master who might start inducing depression with torture, or by cutting off fingers or toes.
You could probably use electric shock to speed up the process
If she only bore him two children in about 16 or so years, then she’d be on the low end of fertility. Very low end. On the other hand, if she had baby boys, he might have disposed of them.