Mine tilts to the side, raises her backfin and shivers when rebelling, and lowers the backfin and the tail when being submissive (like in the pic, but before she did that, she was annoying the male with the shiver dance, as you can see he has that murderous look in his eyes and his body is curved in an S-shape).it looked submissive - it looked like she was saying back off, don't hurt me. Your orange female in the picture looked exactly the same as the one I'm having trouble with.
She's hiding in her corner again this morning
Moving her is a good idea. I think females prefer to be left alone than with a male anyway. Wish I had thought of making a girl-only tank (well, Tzuppy would be an exception, but he's no swordtail so no problem lol).