No Chalet School in my life at present, but I have found a perfectly splendid Angela Brazil story. Sadly the girls have left their Swiss school due to some skull duggery by furriners, but the English school they have ended up with is very ladylike:
Molly and Meg... attended the class for Drill and Deportment held in the big hall by Miss Davis, the gymnastic mistress.
Special instruction was given in how to walk correctly—head erect, shoulders well back, and a graceful carriage. Any girl guilty of slouching or shuffling or swinging her arms was sharply reprimanded...
They were shown the best way to carry heavy satchels or cases of books, so as to avoid any danger of spinal curvature, and were also taught how to bow when passing anyone they knew, with shades of difference—respect for a teacher, head-prefect or a grownup acquaintance, and a more friendly greeting to a young companion
They were reminded of the rule that they must walk not more than three together when returning home, and must never allow the pavements to be crowded with groups of chattering college girls. A Watch Committee, consisting of prefects, were responsible for observing whether these rules were kept, and offenders would be reported when noticed.