Harry glanced into the cracked, dusty mirror and saw Ron and Hermione exchanging skeptical looks behind his back.
"And what exactly did I say?" asked Hermione, her tone somewhere between skepticism and curiosity.
"Yes, but could you keep your trap shut?" said Hermione, looking skeptical.
"But thenů do you meanů" said Hermione slowly, and Harry could tell that she was trying to keep any trace of skepticism out of her voice, "that you believe these objects — these Hallows — really exist?"
There are no more uses of "skeptical" in the book.
Show samples from other sources
I am skeptical about her plan.
She is skeptical any time someone says it is important she pay them a lot for a car repair.