She was being educated at a ruinously expensive school with a number of other inordinately rich little girls, who were all too wonderfully dressed and too lavishly supplied with pocket money.

The school considered itself especially refined and select, but was in fact interestingly vulgar.
The inordinately rich little girls, who had most of them pretty and spiritual or pretty and piquant faces, ate a great many bon bons and chattered a great deal in high unmodulated voices about the parties their sisters and other relatives went to and the dresses they wore.
Some of them were nice little souls, who in the future would emerge from their chrysalis state enchanting women, but they used colloquialisms freely, and had an ingenuous habit of referring to the prices of things.

Bettina Vanderpoel, who was the richest and cleverest and most promisingly handsome among them, was colloquial to slanginess, but she had a deep, mellow, child voice and an amazing carriage.
She could not endure Sir Nigel Anstruthers, and, being an American child, did not hesitate to express herself with force, if with some crudeness.

"He's a hateful thing," she said, "I loathe him.

He's stuck up and he thinks you are afraid of him and he likes it." Sir Nigel had known only English children, little girls who lived in that discreet corner of their parents' town or country houses known as "the schoolroom," apparently emerging only for daily walks with governesses; girls with long hair and boys in little high hats and with faces which seemed curiously made to match them.