Honestly, if shuli married the Duke, it was because of Jeremy and the siblings. His father knew that he was dying and Jeremy was just too young to become the head of the family.
So he just decided to search around for a suitable spouse: young, so she will live a long life and the children will have someone to care for them, with no nobility background, so no noble family could take over the duke's, and finally she looks like the late empress, so shuli was perfect for the part.
Also wtf that priest is horrible and I'm starting to really hate him just shut uppp