I THINK it was shown, or at least hinted earlier on that she was abused until death by the third prince from last ark. Tho why would she develop feelings towards the mc is a mystery to me, maybe he helped her before her death somehow or someshit, as she got reincarnated (revived) with her current body, explaining how it could've happened. Or maybe she just imagined herself in Efils' position as her saviour/prince.
Anyways, for how loco she is, anything and everything can make sense in her case 😜