Well, thanks for the half-chapter, translators :/
That said, I think our MC is going to be schooled on the realities of politics in that world: Emeralda is from a big fish family, so she will not be far away for long ( because it would be politically dangerous for the MC Family to do so ) and her chibi sister was not named heir because of her mother talent in bed, but because of her talent for magic, something that MC lacks.
Why do villains always celebrate early, even when they are the MC?