I think the author has been setting up a drama arc involving heaven's hinted at tyranny for a while now, and Jeanne is the trigger that will lead to the heaven arc.While I find her adorably clumsy, it seems so random and messy to have her realize love now AFTER him having met her parents, Kanan being less tsun as well as meeting his family. It just seems like an unnecessary piece of plot to drag it out. Granted, if the author wraps it up quickly to just put the saint away in the story then I understand that. As they wrote a character for a need but the need wouldn't have been met without this randomness