"She would be stunned and incredulous at the first signs of my gentility," said Rhett, arising lightly.
For a fleeting instant she saw Melanie’s incredulous face, the look on the chaperons’ faces, the petulant girls, the enthusiastic approval of the soldiers.
The hours dragged by and the black shadow of calamity brooded over the town, obscuring the hot sun until people looked up startled into the sky as if incredulous that it was clear and blue instead of murky and heavy with scudding clouds.
Coming out of the front yard was Uncle Peter, a market basket on his arm, and when he saw Scarlett and Mammy trudging along, a wide, incredulous smile split his black face.
She would be stunned and incredulous and would speak gentle words that stung despite their gentleness, would talk of honor and honesty and truth and duty to one’s neighbor.
And, for her penance, there would be the dreadful sight of Melanie’s face changing from fond love and trust to incredulous horror and repulsion.
There are no more uses of "incredulous" in the book.
Show samples from other sources
I find it incredulous that you believe she is sincere.