Fashion Fairy Princess: Buttercup in Glitter Ocean by Poppy Collins (author), Sally Morgan (author), and Pixie Potts (illustrator) (UK edition)

The fairy princesses’ friends are having a party in Glitter Ocean. They’re so excited and set off in a pearl-encrusted shell boat, wearing full-length mermaid gowns. But then the boat gets caught in a glitter storm! Luckily, Buttercup calls out to some friendly seahorses, who give the fairy princesses a ride to the Coral Castle deep in the sparkly sea. But their clothes have been ruined on the hazardous journey! Can they get ready for the party in time?