Charlotte may have been orphaned, but had the good fortune of being raised in a reasonably upscale home run by a respectable Goddess' servants--this means that she was well fed, more than enough exercise to stay healthy--and it shows.  Full-figured and confident, she would likely have come off as some kind of warrior-queen if that was the overall impression she was going for.  Instead, a rectangular set of spectacles, grey-white hair, and a generally stern demeanor leads her as coming off more of a particularly militant librarian--which is far more accurate than she'll admit to on her own.

( General physical features informed by the image uploaded to http://i.imgur.com/Bb0sPsn.jpg )