Wdym? She lost all her memories from when she became a villain so she have the mentality of a 12 yo currently+ she probably acts like that bc she's heavily traumatized
her brother assumed she had her memories from when she was 12 and said something about her maybe having a mentality of a 12 year old, I can back read but it was never 100% confirmed. With that being said she seemed slightly mature in the last chapter, so it might be older then he assumed
Didn't they say she has the mentality of a 12yo rn? WTF is that??