|“|| There is no greater pain or punishment than memory.
Vocal Mind Control
In Queen Song, she tells Coriane that she is looking after Coriane and Julian only for the sake of House Jacos, so she can try to bring it back up to its once greatness.
But Jessamine doesn't hate Coriane. If you read carefully in a couple of parts, it shows that Jessamine shows that she slightly cares for Coriane.
While making Coriane look better for the banquet, she notices Coriane is sad and isn't acting her usual sarcastic self. She notes this and questions her. And before Coriane's wedding, she compliments her figure.
After the wedding, it never mentions much of Jessamine. Not about her death, or how she was doing. So, she probably died of old age.
Jessamine Jacos is a strict woman but wants the best for House Jacos and her cousins. She truly believed that one day House Jacos would become great again. And it did, but not for long. Jessamine loved her family, and maybe she would've been less strict if she more of her family had survived.
She was described in Queen's Song as having saggy skin, gray in pallor, with purple age spots across her wrinkled hands and neck. Later on she complains how her hair is thinning white that it barely covered her scalp.