The Tiara Club: Princess Sarah and the Silver Swan by Vivian French
It's the end of term at Pearl Palace. The magical silver swan must fly down to the lake before Princess Sarah can win her sash. But will the horrid twins spoil the day?
You've met the Rose Room and Poppy Room princesses - now meet their friends in Lily Room as the Tiara Club moves to Pearl Palace! Six more books of princess magic!