Yue and Ruby Moon
I read somewhere that Ruby was actually a guy in the Japanese, and 'he' was a cross dresser. I thought that was strange (considering Ruby has a woman's figure) so I asked around and found some people who watched/read the actual Japanese anime/manga. Here's the deal...
In the original Japanese manga Ruby and Yue were genderless. That's right, they were neither male nor female. Clow did not create them to have gender. They are drawn gender nonspecific. Both are flat chested, both have long hair, both wear robes, etc... In addition, their faces and eyes are nonspecific. Only their human forms had genders (Ruby: female, Yue: male)
By the time the anime came out in Japan, the two had taken on more specific appearances even in their true forms as guardians. Ruby leans toward the feminine, and Yue leans toward the masculine. However, they are still without gender.
In the English dub Ruby is female, and Yue is male. Probably the dubbers chose to go in this direction because in the anime they are drawn with so much distinction. They were dubbing this show for children, they didn't want to confuse them.
Bottom line is this: Ruby is not nor has she ever been male. In the Japanese 'she' is an 'it'. And, in the dub she is female. Yue is an 'it' in the Japanese and a 'he' in the dub. Cheers ^__^