First off, you're doing the right thing by posting for advice. What I'm about to say may seem cold, but it's an outsiders view looking in. At know point do I think she is going to leave her husband. You're just a side dish to her. Her husband is the meat & potatoes, and you are peas & carrots. I believe she is poison to both you, and her husband. That being said, if I were in your shoes, I'd cut this person out of my live.