I think you just have to accept her the way she is. I don't think that there is anything you could do to raise her sex drive. I do think it is good to keep the lines of communication regarding the subject open. Maybe the two of you can come up with a compromise. I've been on both sides of this coin during my life and have never been able to come up with a good solution. Communication is the key, though.
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Bipolar I, Depression, GAD Meds: Zoloft, Zyprexa, Ritalin
"Each morning we are born again. What we do today is what matters most." -Buddha