He couldn't argue with her reasoning. She'd considered using the pensieve to try to uncover any gaps in her memory or any potential false memories, but where would she even begin? For all she knew, every moment of her life before the one she was standing in was a false memory either warped by her damaged brain or planted in her mind by some unknown nefarious schemer. It was possible for someone to go mad if they spent too much time mulling their past in a pensieve. She was afraid to risk it.