Just a random thought:

Is she on birth control pills? As we all know, I am HD. When I was on the pill for a stretch of 6 years, I was DEAD AS A DOORNAIL. No joke. I really didn't have any physical urge at all. I didn't know why, and I didn't care to find out because I was so afraid of getting pregnant there was no way I was going off the pill. Within a couple of weeks of going off the pill, I was ALIVE again. (Gee. Between those 6 years and these 8 years, I sure have missed out on a lot of sexy time. My Mother and the Blessed Virgin Mary (according to my Mother) would be so pleased.)

Did she ever love sex? Before you? In the beginning of her sexuality? Have you had that kind of talk? (You probably have and I just don't have access to your very old posts.)

Of course, DQ is right. You must accept to her what she is right now. It will free her mind from the constant pressure of not being able to please you. (And open it up for forward-thinking.)

Lucky