I don't remember to see any top aquascape only made by a woman. But is strange. I believe that some of the nature aquarium culture, as T.amano said before, came from the Ikebana Japanese flower arrangement that is made mainly by women.
First let me address this misconception.
Ikebana is traditionally a man's art (like most parts of asian culture), and was started by men. Looking on some of the larger ikebana using even large tree branches, one can see how the physical strength of a man comes to play when weaving together bits of tough plant matter. While women have also done ikebana for centuries, and there have been many great femal ikebana masters, still to this day many of the great masters and students of Ikebana are men, and the tradition will always have its root's with men's ikebana.
Even in looking at Japanese garden design and stone arrangement, these are largely male-dominated artforms, and always have been. Can you imagine a noble woman in ancient Japan, dressed in her elborate kimono, having much to do with the sweaty work of lifting large stones, fortifying and training trees with large wooden poles, or raking moss?
Addressing aquascaping, this is a highly technical artform, with all the gadgets and gizmos, ph reading etc. While now there is a big movement to try and get more women into math and science, without a doubt these fields have been traditionally male oriented.
Let's not lie to ourselves-- Aquascaping has a decidedly "geeky" side to it.
Though anyone can appreciate the beauty of the resulting aquascape (and I will say that the ladies love my work), the fact is that in making aquascapes one needs a bit of "Otaku Seishin" (spirit of fanaticism). The devotion (obsession?) required for understanding water balance, memorizing fish/plant species, studying the art, playing with Cameras, etc. etc.-- it lends itself much better to the border-line ADD-ness men are famous for (infuriating women the world over). "Boys and their toys," as they say. The same kind of personality that becomes a car-shop geek, also is suited towards becoming an aquascaper. Rather than having more free time for hobbies-- men
make more free time (at the expense of various other activities generally involved with "having a life" lol).
Finally-- let's face it, between arranging heavy rocks (you need pretty big ones even for an Iwagumi in a 60cm tank) and wood, installing equipment and even doing water changes, there's a definite physical element to aquascaping.
I've thought several times "Wow, if I hadn't done so much wrestling training in highschool, doing that would have been a bitch!" during my aquascaping career (towards a variety of tasks). Things have not changed so much since those first ancient Ikebana artists and garden designers. It's still men who have the brilliant idea to play in the mud, move big rocks and plants, get wet, get hot, get sweaty and icky, and at the end of the day-- maybe put out something brilliant (albeit incredibly geeky).
I'm not saying that women can't be great aquascapers, but most of them lack the personality (insanity?) profile (and back muscles) that generally get involved with it.
