Scarlett turned away from Mammy with studied nonchalance, thankful that her face had been unnoticed in Mammy’s preoccupation with the matter of the shawl.
Never at any time, even in most intimate moments, had he been other than nonchalant.
At first it had annoyed her and she had tried to break down that nonchalance but soon she had come to accept it as a very convenient thing.
How could he be so nonchalant with the memory of such a night as they had spent?
It was going to be more difficult than she anticipated, greeting Rhett with just the proper degree of casualness and, as for telling him about the new baby! She looked at his face as he came up the steps, that dark nonchalant face, so impervious, so blank.
There are no more uses of "nonchalant" in the book.
Show samples from other sources
I could tell she was nervous, but she was trying to look nonchalant.
How could she be so nonchalant about making him suffer?