Cinder wouldn't risk it here, to be honest, so she'll have to pass to keep her true identity secret yet. Although as far as good guys go, I can offer Mikasa, Ty Lee, Rikku, and Ruby.

Although, Mikasa isn't likely to stick her neck in it unless given a reason to so she's tentative. Ty Lee probably wouldn't do anything about it unless Azula or Zuko or Weiss were involved somehow. Rikku and Ruby are also tentative, but they're more likely to do so.