There seems to be some truth to the stereotype that women are more oriented to relationship. I do think I notice that women are brought in to Tibetan Buddhist groups via family relationships and lovers. Then it seems that women often sacrifice their own time for personal practice either to their family/partner's needs, or to the needs of the lama and center for help. I'm not saying that is negative. There is always a push pull between our Bodhisattva vow and taking time for practice--be it an hour or three years--isn't there?
Specifically to lesbians--we have had at least three complete three year retreat at our center, so we are no slouches. And two more went through another California Druptra. But, for beginners, it is very difficult to get beyond the aversion to organized religion, given that it has been so rejecting. And it's not all in the past tense, the kind of rejecting and pseudo-tantric baloney talk I've seen posted by participants on this forum, for example, doesn't help. So, there are big obstacles to taking refuge. Then, one needs to trust a teacher, enjoy the imagery, learn a little, and feel it is valuable to spend one's time and energy practicing. If we had a lesbian lama leading Throma cycle practice, for example, I would imaging there would be hundreds if not thousands of lesbians drawn to that, and some practicing regularly... because women are hungry for the fierce feminine. Is that kind of insular? Yes. But there are reasons for that, and the Vajrayana has countless skillful means for all kinds of sentient beings to be tamed. The guru yoga dynamism of Yeshe Tsogyal and Guru Rinpoche magnetizes some, and between Throma and Vajravarahi (in the Throma ngondro), others.
Remember Fred Brown? He departed for the pure land a few years ago. When I was checking out Lama Tharchin Rinpoche in 2007 I remember over-hearing a conversation where two new gay men asked him in the bookstore whether Rinpoche was comfortable with us gays and lesbians, and he reassured them. That sealed the deal for me. It sounds like we are all children, needing reassurance like that, but a relationship with a lama is intimate, and one needs to know that one is loved and accepted through and through before embarking on such a thing.