Maren was VERY beautiful and they made quite a striking pair.
I think the main reason she didn't act very much in later years is because she was diagnosed with Epstein-Barr (chronic fatigue) syndrome. Don was quoted in the book "To The Limit" saying that he took her to several doctors before it was finally diagnosed, and the whole situation became very difficult to deal with: "I was dating this beautiful girl who shortly thereafter became practically an invalid. She was literally in bed for a year."
He goes on to say in the book that "Maren & I stayed together until 1986. It was hard for her because her career had been cut short by illness and by the time of my second solo album I was starting to make it big again.....Finally she moved out, partly because of some reprehensible behavior on my part.... I felt a great sense of sadness."