I just read something on another post (#1142002) that sums up better than I could what I feel the real problem is:
"I personally think that HD/LD consists of more than just frequency, but the actual ability to express desire for someone. My H will gladly ML once a week (now anyway). If he could show desire for me through out the week and build up the anticipation of our ML I might be content with that. However, we have a pretty platonic relationship up until the point we do ML. It almost makes the once a week seem meaningless."
This is from a wife's point of view, obviously, but the point is the same: it's about knowing that you're desired, and building up the anticipation before the act. If she could do that, I'd be the happiest man alive.
She's told me before that she doesn't know how to initiate communication about sex, even though she says she wants it at times.
Her religious upbringing and social conditioning are responsible for this hang-up, I believe. She has overcome many things in her life, though (which I admire her for). Maybe she can overcome this ...