@Romashk when did she jump 5 meters high? she was dropped into the water by her brothers magic, then saved by the impact of the water.
if you recall, the fairy said that she can see in the dark, see fairies, and negate magic, not fly.
@scudder because its always been that way. nobody, unless its a grand duke or emperor, can overpower a duke that has RELATIONS with the royal family. the grand dukes also been played like a puppet by the emperor, so hes seen as a monster with no power. so basically even in other villainess manhwa, when the mc is clearly being abused nobody can stomp up to the dukes mansion and go wow this is sus!! so to answer ur question, the logic is power. the mcs father has power and no one usually questions it or questions the disappearance of the daughter + the emperor is part of the plan to use mc. and the duke is so used to controlling his daughter that locking her up for a week is nothing to him