The more I have listened to actual Kansas natives, the less I think she’d have a drawl. I think her “otherness” that Helen could sense is more from the way she carries herself and her unfamiliarity with city life. I have yet to find any celebrities who sound like her in my mind, although I have been practicing on my own to make a voice for her.
I have been thinking about doing one of those interview-style recordings like other Supers had on the original Incredibles dvd extras. I just need to come up with something for her to say, lol.