Re: Mental myopia...
Because if you were allowed to shag your sister-in-Faith, then the Quran would have allowed other women to be a woman's "na-mehrams" or people she can marry with. You would also have seen examples of it in the Sunnah, since you people love to cite Hadith's for examples.
If you can find a lesbian example, then please put it forth. And if I'm not mistaken, there is a direct verse in the Quran that says specifically that your same gender is not allowed to you.
Homosexuality is an umbrella term that encompasses male-male relationships, and female-female relationships.
Placing a female-female relationship as an exception to homosexuality is actually an impression and cultural value that can be traced back to the greco-roman empire.