@Wolvenworks
@hersheyz
@gamma2015
@Renan_Walheim
@Lioslin
She most likely is the sister from the story who was part of the siblings who had the "dangerous power"
It appears brother ( and probably sister too ) had some kind of power to change bodies somehow.
The most likely scenario to me is that she used hypnosis and/or illusion magic on herself any anybody who visits ( probably with the help of the sun magic stone )
So that she would not be aware of the time passing to prevent herself from getting bored ( she said she " completely woke up ", implying she wasn't in the first place )
I think the trigger for her waking up was telling somebody her name " Marom"
The other darker reasons I can think off is that she is the sister of the demon lord.
If that is true then she could likely be some form of an angel( who possessed the body of the girl ) because of thematic reasons and what little we learned from the first few pages.
She could have made an underground human farm with clones from dandelions, to get a better body for when she was ready to possess a body and leave the underground.
Once she got her body and was done with the farm, she made all the other clones revert into dandelions,(which is why only the people and the Cicada body transformed..only organic stuff )
This is supported by the fact she "thanks" her parents dandelion flowers at the end, it would make some ( but less ) sense to thank an illusion instead of a dead clone.
But all of this is just a guess.
We probably will get some kind of explanation later on, but this is most likely not the start of anything good...