The Getting of Wisdom by Henry Handel Richardson

It was an odd thing, all the same, how easy it was to be friends with Lilith Gordon: though she did not belong to Laura's set, though Laura did not even like her, and though she had had ample proof that Lilith was double-faced, not to be trusted. Yet, in the months that followed the affair of the purple dress, Laura grew more intimate with the plump, sandy-haired girl than with either Bertha, or Inez, or Tilly. Or, to put it more exactly, she was continually having lapses into intimacy, and repenting them when it was too late. In one way Lilith was responsible for this: she could make herself very pleasant when she chose, seem to be your friend through thick and thin, thus luring you on to unbosom yourself; and afterwards she would go away and laugh over what you had told her, with other girls. And Laura was peculiarly helpless under such circumstances: if it was done with tact, and with a certain assumed warmth of manner, anyone could make a cat's-paw of her.

That Lilith and she undressed for bed together had also something to do with their intimacy: this half-hour when one's hair was unbound and replaited, and fat and thin arms wielded the brush, was the time of all others for confidences. The governess who occupied the fourth bed did not come upstairs till ten o'clock; the publican's daughter, a lazy girl, was usually half asleep before the other two had their clothes off.