Photo: Damon Winter/The New York Times; Video: By REUTERS

Mary Pat Christie, the wife of Gov. Chris Christie of New Jersey, was a picture of stoicism throughout much of Donald J. Trump’s meandering victory speech on Tuesday.

Until, suddenly, she wasn’t, seeming to betray a combination of bewilderment and dismay that instantly went viral.

In the final moments of his Q. and A. with reporters on Tuesday night in New York, Mr. Trump posited that the only reason Hillary Clinton was winning was because of her gender.

“The only card she has is the woman’s card,” he said.

He added, provocatively, “If Hillary Clinton were a man, I don’t think she would get 5 percent of the vote.”

The look on Mrs. Christie’s face immediately changed. She slowly turned her head toward her husband, appeared to roll her eyes in disapproval and smirked slightly. Then she looked down at the ground.

Her husband may be Mr. Trump’s biggest supporter. But there was no denying it on Tuesday night: Mrs. Christie appeared to have misgivings.