It’s probably stagnated at least considering she basically is reliving acting like a child. I think it’s like Conan. They both act like kids so much that their behavior changed a little bit. She has it worse since she’s had no serious situation which requires her to act her mental age and was raised from birth to now, not just elementary school. She also doesn’t have anyone who she knows that doesn’t treat her like a kid and likewise no one she has to save face from.
Which I kind it kinda sad tho in the story it doesn’t show it. I’m pretty sure if you put this as a real story there would definitely be a time where she wants to talk to someone about her past or smart plans. I wish she would tell that unknown human/species Dante(?)
I kinda forgot that she isn't "actually" like eight years old. Did her mentality just change to fit her age?