I don't know korean, but has Estella been using "appa" for "daddy"?
Like, I feel like she's been refering to him in a casual way or there are more layers in korean, if "abiya" is father. I might just have brain-farted playing 4D grammar terminogy.
@Fajken It would certainly be a nice change of pace. Though fortunately not utterly unique in manga/manhwa (no idea about manhua), but the Western fairy tale traditions at least have created the expectation high-born stepmothers are going to be evil.