The upcoming update to the game will have more than just Mr. Drape added to it. Sarah will be joining the cast as well. As a student, she will be available to join your party if you want, and will also be fairly easily enslaved for the sake of introducing in-conversation spell casting.
Personality-wise, Sarah is an extremely self confident person to the point of being somewhat egotistical. Her self confidence is genuine, so she tends to lose her confidence when faced with a situation outside of her own ability to handle.
I have not yet made any of her alternate personalities and costume changes. So, if there is something you would enjoy seeing, feel free to let me know in the comments.