Christin
You are treading on very dangerous ground when you involve yourself in someone else's marriage especially at that level. Even though she is a friend it's advisable for you to back away from it. If you feel you need to be there for your friend be a listening friend, not a advising or problem solving friend. She needs to be sitting down with her husband and communicating with him about this very personal issue as a first problem solving action. If he isn't open to discussing it with her she needs to seek out a marriage counselor. If he isn't willing to join her in seeing this counselor she needs to go alone. At the least this action may help her emotional state and give her some relief.
As you've stated this isn't a new problem. She had a bad experience with a previous marriage. This probably left her feeling insufficient and very insecure about her sexuality. I'm sure she is very emotional! What kind of relationship did she have pre-marriage with this current husband, or do you know? Did she have a sexual relationship with him? Did they discuss sex at any level before marriage in regard to their personal feelings and emotional feelings on the subject matter? Was her ex-husband her first sexual experience? I'm sure her current husband does feel rejected, leaving him feeling inadequate and unattractive as well as undesirable in his wifes eyes. Those feelings are very damaging for anyone to feel.
My guess is her religion is playing a big part in this entire situation that she is dealing with both emotionally and mentally, as well as her parents and family being accepting of her discussing this problem with them. Is that correct? I doubt that she is too depressed to explain, if she came to you with the problem to begin with. Have you offered to help her find a counselor, maybe even go with her if she has to go alone? There again you need to remain a silent participant, especially there. However your being there physically may give some comfort and support.
I wonder if she meets the requirements that a immigrant seeking security would be required to meet? Don't know any thing about what those requirements might be. Have you contacted a ambasador to her country to find out? Or has she done that, or do you know? As you can clearly see the question you pose leaves a lot of unanswered questions that really do need answered before any thing else is done.
Good luck to you and your friend my heart goes out to you both in this very difficult situation.