might be a bit of a stretch

but consider,

she speaks in a monotone voice, even after being prompted to repeat herself in a "more cheerful tone"

introverted to the point that the classmates that knew her from middle school consider her "creepy"

doesn't make (or hold) eye contact while talking to most people

imitates her dog

idk, I get she's supposed to be "kuudere" but what if?