Alice-Miranda at School (Alice-Miranda #1) by Jacqueline Harvey

Can one tiny girl change a very big school?

Alice-Miranda Highton-Smith-Kennington-Jones is waving goodbye to her weeping parents and starting her first day of boarding school. But something is wrong at Winchesterfield-Downsfordvale Academy for Proper Young Ladies. The headmistress, Miss Grimm, hasn't been see for ten years. The prize-winning flowers are gone. And a mysterious stranger is camping in the greenhouse.

Alice-Mirance must complete a series of impossible tests. Can she really beat the meanest, most spoilt girl at school in a solo sailing mission? Could she camp in the forest all on her own for five whole days and nights?
Well, of course. This is Alice-Miranda, after all.