Dorothy is different from all the other women, mainly because she loves war. And when I say she loves war, I really mean that she loves war. If war were a man, I'm sure she'd seduce him and happily bear many of his children, but I digress.
Now the crazy eyebrow chick, which she is called lovingly- and sometimes not so lovingly- does not necessarily love war for being itself; she just loves it, because it's the only thing she knows. Her mother died when she was very young, so she was raised by her father, a general in the Alliance military.
It is not exactly stated when he died; but, when he did, Dorothy went to live with her grandfather, Duke Dermail. Both of these men probably had very little knowledge on how to raise girls, so she was brought up as a boy, learning how to fence and most likely sitting in on battle planning sessions.
Dorothy was the last woman we meet in the series. She had been sent by the Romefeller Foundation to the school that Relena had founded in the Sank Kingdom for the girls of peace-minded nations. Since Dorothy is almost the exact opposite of Relena, the two would often argue over war vs. peace, even though Dorothy genuinely respects Relena.
Dorothy's entire purpose in going to Sank was to bring Relena to the Romefeller Foundation. With her country falling down around her ears, Relena finally consented, and Dorothy took her to her grandfather and the rest of the Foundation.
After that, Dorothy does not really play a major role, until she joins with White Fang and confronts Quatre Raberba Winner, pilot of the Sandrock. She challenges the blond Arabian to a duel, while controlling the mobile dolls with the Zero system. Their duel is one of the most interesting and intense scenes in the series.
While battling with her, Quatre tries to convince her that she is a good, kind person, but Dorothy does not listen and- perhaps to prove him wrong- stabs him. This ends their fight, and Trowa helps the injured Quatre away. On his way out, the quiet pilot comments that it is sad when a woman cannot cry; and Dorothy, shaken by his words, begins sobbing uncontrollably.
Not only is Dorothy strong of mind, she is also strong of body. She managed to use the Zero system, without it controlling her, which is something most of the gundam pilots could not accomplish. While doing that, she was fighting with Quatre, talking to him the entire time. She even stabs him with a foil, which bend normally and do not cause serious injuries to people.
I, for one, like Miss Cockroach Brow, and she is not as insane as some people make her out to be. In fact, she is much saner than most people in the Gundam Wing universe i.e. Tsubarov or Alex and Mueller.
