This was not the first time Princess Peach had seen her dark side. She already knew exactly what the potential for evil inside her could lead to if she allowed herself to fully unleash her prodigious magical talent without any kind of self-restraint. There had been a reason she did not ask Twink to allow her to wield the power of the stars herself. The ability to grant her wishes, to give life to her every whim... she could not trust herself with that again.
It was wrong that a human, a species that ate mushrooms, had ever been allowed to rule a Kingdom of mushroom-people, and her family's conquest of them had not been pretty. Her family had known that Bowser's Magikoopa division had trapped the captives inside soul-cages on that day but had still let Mario, their clueless champion, shatter the cubes without thought to its effect on their inhabitants, absorb the essence imprisoned inside them to aid his further conquest of Bowser's lands in the Toadstool name. They had known and had not cared, because those captives had willingly surrendered instead of holding out and believing in their Princess. This was the sort of people they were. That hereditary insanity was already coursing through her veins. She felt the mood swings every night, used far more mind-magic on herself to control them than was healthy. Not to mention that no human should be that good at mind-magic in the first place. She had even seduced a machine. She had been tempted to put the supercomputer to such grand, ambitious uses... all for the good of the Mushroom Kingdom, of course...
No, she was not a person she could trust with great power, which was unfortunate in a ruler. Maybe that was why she insisted on referring to herself as 'Princess' when there was nobody standing in her way should she decide to officially ascend to Queen? And maybe... just maybe... that was why she kept subconsciously slipping up all the time, allowing Bowser to kidnap her all the time.
Sometimes, on the darkest nights when it was hardest to control that 'other' her, she wondered if it wouldn't be better if she just admitted the Kingdom was safer with Bowser anyway. She soon realised it wouldn't work, though, whenever she caught a glimpse of the Koopa King's face and realised that he was already under her control.