>>65292610lurkerzoku here, to backseat as another kenzoku, in regards to characterizing Towa in a true to life manner, I think the flaw fundamentally as you've written her is that she's a bit too naive/embarrassed easily, without any real bite back to her, a large portion of Towa's charm (to me) is that she will alternate between that bite and sincereness, or as others call it, her mental instability, her ability to switch on a dime. I think if you develop her to have some confidence and be more independent, closer to her confidence at the start of chapter 1,
and not a remote controlled car with that slight bite, I think you can achieve a more true to life portrayal of her. I think you have the sincerity and a bit of her naivete down and the scenario of which is honestly quite good for this scenario.
I'm not sure if you've read the official holomanga with Towa, but I think it achieves a slightly similar idea, thought different, of what you're doing of throwing Towa into a very new scenario and showcasing her naivete and eagerness to learn but still allowing her to have some bite/straight-man appeal to her.
(https://alt.hololive.tv/holonometria-en/manga/underworldacademyoverload-chapter1/)Regardless, I do enjoy the story and am thankful someone is writing a consistent fluffier/happier story, not everything has to be perfect to life, it's fan fiction after all. I don't think you've "failed" in characterizing her.