
It's her father, but probably step father.
The real owner of this noble house was Grace's real mom. This father married into the house. But people don't like him. They think this guy is never enough to rule or act as a proper Lord of the field.
And apparently this guy, after Grace's mom passed away, secretly found himself a wife and fathered a new daughter without anyone know.
And because the next heir to the house is Grace, this father & his wife planned to poison Grace to death so they can took the inheritance.
But suddenly, the King propose a deal to the father that if he offer Grace to marry the Duke, King will give this father lots of rewards.
But at that point, the original Grace was in coma, so the father try hard to revive Grace.
In the end, original Grace died and new Grace awake.
Wait am I the only one hella confused? Like why did her father revive her after he poisoned her? Also why is he even acting to nice to her at this point if he hates her so much to kill her.