"Sometimes... I feel like Pession is more like an adult than I am, even though I have memories of my past life."
He surely is! Just a few of the brats in the gathering are more like a kid than her. It's more like she never grew up entirely (socially/psicologicaly/emotionaly) before, and what's more, whatever the mess her mother caused to her before is still impacting her thought process for everything.
It's sad to see her thought process sometimes, but it's even more sad to think that thinking like that is real for some people because of what they had to go through.