this is complicated. People in previous chapter keep saying that this wasn't adult woman's behavior, but it's been hinted from the start that Marika is still in there. It's just that Takae's mind has control mostly
Takae did not take control of marika's body. It's the same reincarnated soul. It;s just that the many years of memories flooded and overwhelmed the few memories the child has. How much do you remember what happened when you were a kid?