If she has a good battle logic, I will use her, but if she is hella OP, and everybody's using her, then I won't use her. (You can see I don't run with the crowd)
Systema is a quick and deflective martial art. She may not be a grappler, but a sabaki-heavy character, which is something I would love to see. I would love to see her have a deflect stance, that can like, turn into a throw animation or something. Like a hold, but not a hold.
Anyways, you may be thinking "What is this 13 year-old talking about?", but I think she will have those things listed above and a frickin' mental combo method, with a average ground game. You see that Lili-esque down attack she has? Damn.
They can just balance her good enough NOT to be a spammable chick.