But that 2nd seat girl still seems to hold a very deep bond with her little sister, that grandma. Do blood ties take priority over the "dragon kinship"?
According to what we have seen already 100% would abandon her for her King's sake. She would grieve but wouldnt hesitate to kill her and her entire family if needed.
Look a certain King casting away his family in a whym and creating another soon after, or how Artemisia grieved for humans but still killed them, or the dragon of the Bloodline of the Roars who was killed by Ragna just before ,during his first appearance how he was eating a butchered human snack . Future Ragna himself when he was turning into a Dragonkin was feeling how his feelings and memories started to twist before he stopped the progress by stabbing himself with his silver blade
The only one that acted beyond their boundaries was Ortho Zora because he was obessed with his former master that also was the object of his love to the point he had a split personality one being more human like and the other more dragon like, so it seemed a very specific situation with a specific person