... the avatars of the first two responses to this thread are both funny and make me unsure if they're a joke or not. =D Because all I can imagine is the wide eyed Klingon saying, gruffly, "I'm a lady".
Anyhow, there are definitely some women playing the game, but I'm not sure that there are a bunch. My wife does play from time to time, and there are a few more well known ladies here on the boards. In fact, there was actually a thread where quite a few chimed in a couple months back because a similar question was asked; you can probably track it down if you're so inclined.
I do agree that these kinds of space sandboxes can lean quite heavily towards being mostly men-folk, and on the surface ED doesn't appear to be much of an exception in that regard. But you are definitely not alone, if that's if your worry!