Hi. Here is the perspective of a lesbian who has had a similar problem with my girlfriend: We were just not "happening" and we decided that we both needed more distance in order to keep the spark alive. Frankly, at the time we decided to make these changes we had not had sex at all during the prior 3 months. We moved into separate bedrooms, started putting more energy into ourselves as individuals, going out at night and doing different things [taking a class, seeing friends, just hanging out alone in our rooms] and ta-da: We have us some fire now. I think in general you need to replicate your life when you first met and were passionate. Things are going well for my girlfriend and i now.

I hope your woman can find herself again. I think she will find her passion sitting next to her self.
best to you both,
Hopeful Camel