I recently reread The Lost Heir and couldn't help noticing how weirdly Moray behaves around royalty, and I had an idea.
When Orca was preparing to challenge Coral, she placed the enchanted statue in the hatchery in preparation for her queenship. That might not be the only spell she cast. What if she also enchanted Moray to be fervently loyal to her queen and hate any potential challengers?
Moray is her cousin, and although she wouldn’t be eligible to challenge Orca, her future dragonets would (as is the case with Tundra and her dragonets). So it’s reasonable that Orca could view her as a threat. If she were enchanted to hate any heirs, Moray would discourage her dragonets from challenging for the throne, or even go out of her way to inhibit them - if she even had dragonets at all.
Orca would’ve cast the spell shortly before challenging Coral, as she did with the hatchery statue. But when she lost the battle, her enchantments remained. Moray is still fervently loyal to the queen, and dislikes any potential heirs - only, she’s loyal to Coral, and hates Anemone.
And maybe that's not the only spell - Orca could've cast a lot of enchantments that we don't know about.