They can
Investigative night results should be claimed ASAP usually if they look fairly accurate, otherwise that only implies the invest is looking for a response from the player/s in question first, to see if their claims collimate.
Assuming she really still can figure classes and see if her target attacked someone, Reborn's response could be useful to catch a lie, not sure how useful NW's would be though. Because he can still claim Paladin and easily feign a night action result.
So she should simply be more aggressive on him.