Jenny "Smellwether" Slate has kind of a squeaky, youthful voice to her, more like that of a teen or college-aged babysitter as opposed to a June Cleaver type. So I like the direction they're going with.
Also, Nanny seems to have ditched her trademark striped stockings, or at least varied her wardrobe beyond that. Notice the dragon pattern in the first shot, and airplanes in the next, which could relate to the theme of the episode. Reminds me of Miss Frizzle and her dresses.