People questioning the use of an act that is being confused with another, doesnt make them unreal. There is a difference between Sexual Harassment and Rape. If a person gets taken to court, they will face different levels of punishment for the two crimes.
Also , its extremely judgmental to just tell her to divorce and move on. Lets face it, if she could she wouldnt have married him in the first place. she has a family with him now. OP still hasnt clarified what kind of a husband he is. What his personality is like. what he is like to his own kids. whether this friend has any form of professional help available to her.
Its much easier to tell someone to divorce. Put yourself in their shoes and their personality and you would know how hard it really really is on a woman and the kids involved. you and I are no one to make decisions or crude judgement on her behalf. She has chosen to remain with that person and bear his children. there must be some reason why she is still carrying on. if eventually she decides she doesnt want to be with him, she will take the steps necessary to mend her life and soul and she wouldnt be wrong in doing so.
But right now, the OP has asked how they can support their friend. They havnt really asked us for a judgement on her divorce. I believe many posters here are only trying to help the OP in ways to determine how good or bad the situation is with the lady and then help her accordingly.