Tom Tackles the Chalet School by Elinor M. Brent-Dyer

Tom Gay is a new girl at the Chalet School who has been brought up like a boy by her father. She struggles to adapt to school life and see things from a girl's perspective. Adventures follow, with excitement at the school's annual sale, the threat of midnight burglars, and a special picnic for the girls. Will Tom come to appreciate the Chalet School and its charms?