I still think she the culprit I don't know why, u never know a lot of stories make the villaines the sweets considered people, but they had be the cruelest,especially the fact she was likey to succeed the thrown if she had talent like her other siblings,or one of her brothers,I feel like the closest to u is more likely to betray u
I'm quite sure it's her and her husband. Before it was also obvious it was Jessica same thing can be applied here. And she has more than enough motive. if her husband truly loves her it would explain why he helps and he also might gain something else in the long run if killing Liz isn't the endgame but destroying the whole country.
Honestly thought the missing princess was the culprit but it turns out she is a sweetie and married off already lol. I wonder who the villain is