Does anyone have the convo between Stefan and Micaiah when you recruit him with her? I've never done it, (I always use Mordecai or Lethe for it) but I'm guessing the only reason he appeared to her was because she's branded and he wanted to help out one of his kind.
Maybe their branded scent wears off the older they get. Like with Soren, in his info convo with Ike in endgame he talks about how he passed by many laguz on his way to Crimea and how they sensed him and hated him for what he was, but all the laguz he's been hanging around recently haven't said anything about it (Ranulf, Skrimir, Tibarn, Reyson, etc.)