If she confonts her boss that would end badly. Have her go to HR and at least it would be doument on her boss's record.
My wife works in HR and some of the stories that she tells me are amazing. I always thought that HR was neutral between the employee and the employer but apparently thats not the case.
She told me that there are the files that the employee can view and files they arent allowed to view. The latter has all kinds of things on the employee such as complaints to HR.
What she has told me is to document everything yourself and include dates, times, names and an accurate description of the event. She said not to go to HR because depending on the employer that could do more harm than good.
She has told me that she has witnessed someone meeting with an HR rep. As soon as the meeting was over the HR rep calls the complainers boss and they discuss ways of terminating the employee.
After hearing some of the stories from my wife, I have very little respect for HR anymore...
Good luck in your situation.
My suggestion would be to have your wife stick with it but look for another job if it's bad enough.