It really sounds to me like she's simply never discovered what makes her tick sexually. Don't despair, I was once LD myself....as were other women who participate on here. It can change.
Does she have any female friends that you think may be HD that you could encourage her to hang out with? Women who are LD have a bit of a habit of hanging out with other LD women....and they tend to foster an opinion that men just want "SEX". It just so happens that all of my friends are women I would consider HD women, like myself now. Not one of us would talk in a derrogatory manner about sex. You know...now that I think about it....at least 3 of the 4 women I'm very close friends with used to be LD and are now women I'd consider HD especially when listening to them talk about their M's.
