User blog comment:B214/Chapter 513: Hanamaru/@comment-4507125-20161205155546/@comment-7418318-20161205161721

Could be that he only knew her in her Dragon form, but he should have recognized her by smell if nothing else.

With her magic she might be able to change or mask her own smell, but then why would she still smell the same as her supposed daugher? One way or the other it makes no sense, with the information we have right now.