@Kt Well it was because
Spoiler!
Cha Mi Soo told her to give baby Eirin into the collateral branch of Etham house so that she doesn't attract attention and her powers aren't discovered
I like to post spoilers for the stories I find interesting because I don't have much time to read novel due to busy schedule
you will find me in most romantic historical manhwa comment sections 
you will find me in most romantic historical manhwa comment sections