The single most important thing you can do to get a woman to be more interested in having sex is to make her feel comfortable, and reassure her that sex and her enjoyment of it, are healthy and desirable characteristics.
Contrary to popular belief, a significant majority of women are already interested in having sex. Claims of womens' disinterest in sex is widely suspected of being the result of internalized shame and feelings of guilt over the freedom of their sexual expression, not an innate inability or lack of interest in sexual activity.
Similarly, also contrary to the popular belief that sex "comes naturally and you will know everything to do," no one is born with any innate knowledge about the intricacies of sex, only the instinct to desire it.
Understanding low sex drive in women Edit
There are many potential causes of what may seem to be a "low" sex drive. According to an article at WebMD.com:
When low sex drive is health-related, experts say, the solution is easy.
"For some women all it takes is a little dab of either lubricant or estrogen cream on the clitoral area. You can't believe how many women suffer, not realizing how easy this problem is to solve," says Northrup.
But while for some women the answer might be as close as that tube on the nightstand, Sadock says, for many others the lack of libido is intimately linked to the complex emotional algorithm that makes up a woman's sex drive.