In case you have forgotten about it, even before meeting Aster, the pink-haired girl didn't take part in her family's activities, namely scheming against basically everyone but especially between relatives, from the very beginning, unlike everyone else from the Karel family.
Mylene was a cheerful and carefree child, a princess at that, and she remained unaware of the nature of her family until she was six years old, then she suffered her first assassination attempt the very day of her birthday celebration, a single year after she became able to cultivate.
That was also the sole time she met Eris before they treated each other as enemies, and it was in part thanks to that that the heavenly rose princess vouched for Mylene to not be killed, because the difference between the kind and bubbly pink-haired princess-like girl she met that day and the ruthless enemy that relied in all kinds of schemes she had to deal with after meeting again years later, was too large.
