Maybe.. 

Gundam.

Maybe you saw a poster of her somewhere and subconciously drew her? Because the resemblance is too uncanny to be a coincidence. She's a fighter, she has that hair, and that jacket?

as long as you drew it yourself, you can draw characters from anything you like.

I can assure you I didn't know this character.. where is she from?

Looks an awful lot like Rain.

this would look great with a simple idle animation :)