How to (almost) ruin your school play Book

"Rule Book #4" of the Willimena Rules! series. Willie's older sister Tina has written a play that's been selected to be produced as a school play. Willie longs to play the proud fairy princess but her audition goes badly and she is selected instead to be one of the trees. Rehearsals go from bad to worse when just before the big night, the boy acting as Prince Igor loses his voice. Willie steps forward to play the Prince because she knows all his lines. The play is saved and Willie earns Tina's gratitude.