I'm not a huge fan of the design you've put there. I guess it makes sense if they're doing a more "homegrown" angle on Cassie's origin but I don't love it myself.
That said, I'm not against her being a bit cute. Heck, original series Cass had her cute moments here and there. Just as long as she is a fighting savant who has a specific relationship to combat and death. That's what I want.