Kind of belated, but it's ocurred to me that one potential challenge of writing an asexual relationship in femslash is that there's an old stereotype about lesbians not having sex (I'm not sure where it comes from. Maybe from the idea that sex isn't really "sex sex" unless penetration's involved?). I think that would be more of an issue in original fiction meant for a mainstream audience who've never heard of asexuality and don't know much about bi or lesbian women other than what Hollywood has told them than in femslash that's going to be read mostly by a fannish audience that's predominantly female, queer, or both, though.