So im guessing her mom is the demon lord and her dad is the oldest son who passed away he ...

So im guessing her mom is the demon lord and her dad is the oldest son who passed away he came to kill the demon lord but fell in love but he was already injured/sick maybe and died and when the black haired guy came to kill the demon lord she was being sus n just accepted death easily im guessing someone helped baby bunny escape and Ruri her guardian must be a transmigrator and came searching for bunny and raised her to not become the Villainess