Yeah, I mean, sooner or later the secret is going to come out. Retsu's a shitty liar so the only way she can hide her ninja identity for so long is if no one asks her. And she may not even bother to hide her ability when the going get's rough, or at least try to play it off as a "really tough peasant". It's just you know, with ninjas one of their most valuable resources is surprise. They have to be able to surprise not only their enemies but they allies too. Like I said, not that it'll matter in the long run, but I also would like to play out Retsu fumbling to keep her ninja identity a secret.