Her lawyer, Steven D. Altman, noted how commonplace texting while driving has become. “It’s going to be very difficult for her to deal with the fact that at sentencing she could be incarcerated for something we are all guilty of doing on a daily basis,” he said.

The pedestrian, Yuwen Wang, died days after the collision at a hospital that is next to the courthouse in New Brunswick where she and her husband, Steven Qiu, had said their vows six years earlier. The couple had celebrated their anniversary the night before the crash.

Mr. Qiu said he and his family were comforted by the verdict. “I’m really grateful,” he said, adding, “I hope more people could realize the consequences of texting while driving.”

His wife’s final words to him came in the form of a cheerful but mundane farewell. “Have a good day,” Mr. Qiu recalled her saying.

The text at the heart of the trial was equally ordinary in a culture where streams of shorthand cellphone messages have become ingrained in modern life. “Cuban, American or Mexican. Pick one,” Ms. Mansonet’s former sister-in-law had texted to ask about her preference for dinner choices, the assistant prosecutor, Christopher Decker, said in court.

Where and when Ms. Mansonet read the text, and when she had begun to tap out a reply, became central to the trial in Monmouth County Superior Court in Freehold. The prosecutor argued that the unsent text — the letters “m” and “e ” — were the start of a response about her dinner choice.

Ms. Mansonet willingly turned her phone over to the police after the crash, Mr. Altman said before the verdict. Had she been using her phone to text at the time of the crash, Mr. Altman said, “all she had to do was delete it.”