I would be willing to believe that she told him because she wants his help. That would be, his help to do what she decides is the right thing and when she decides it’s the right time.
She clearly doesn’t want him to fight this battle for her, fair ball. But she wants something or she wouldn’t have told him, I believe. She didn’t want to tell him for fear he’d over react, perhaps because he is an HR guy.
He should do something. He should, gently and with care, encourage her to please document the events as they occur, please, please. So when the day comes that she has had enough or she feels it’s time, she has what she needs to act decisively. Additionally, as she has let him in on what’s going on, he should inquire, not daily perhaps, but regularly how things are going in this relationship. Simply stay on top of it, and stay informed. At the same time letting her know that he continues to be concerned. (No. Not in an overly parental way. In a friendly way.)
From time to time, he should offer her suggestions, the sort of more reasoned ones being offered here. The one about going to the company lawyer seemed a good one to me. An anonymous letter, without her name but pointing out that what’s occurring is being documented. A one on one discussion with the guys uncle, in private, pointing out that she is not, by nature litigious but is afraid of her life being made miserable should she speak up, she loves her job etc, (again, mention the documentation that’s hopefully being kept.) It sounds to me like at least one other person at her work knows about this, which is a good thing.
Just keep coming up with creative solutions and throwing them out there in an easygoing, “Hey, I was thinking about your situation…”, kind of way, like a friend would. Then leave her some time to think them through and get comfortable with. After a little reflection, and possibly another bad day, she may latch on to one of them. One may suit her, and her particular situation, just right.
Mostly though he needs to not ride her about this, inquiring is okay, grilling is not. Throwing out suggestions is okay, pounding away on the one he thinks is best is not. Mostly though, not being offended that your suggestions are not being acted on, is the more important thing.
I feel she is trying to become a person who can handle this herself. Perhaps understanding that he’s abusing her in this way because he senses weakness there. As an adult she deserves the opportunity to evolve as a person and deal with her own stuff, and in her own time. And her husband should support her in that personal development.