Thankfully, we've not run into a Mr. Stud/Mrs. Dead Fish combo . . . but I'm inclined to think that she's either very sheltered and doesn't know how to "let loose" in bed, or is simply lousy at sex.
That said, I'm with Ivory Towers in wondering how she could just lie there while other women are making noise and moving around.
Lord help that poor woman if she ended up in a room with me . . .
=)