TAUNTON, Mass. — Michelle Carter, who encouraged her boyfriend Conrad Roy III to take his life in a series of texts, is now serving a 15-month sentence in the Bristol County House of Correction after a judge rejected her request Monday to remain free while she appeals her involuntary manslaughter conviction to the U.S .Supreme Court on First Amendment grounds.

Carter, her once-long blond hair cropped short, was led out of Bristol County Juvenile Court after a hearing before Judge Lawrence Moniz that lasted less than 10 minutes.

“This has been a four-year ordeal for our family,” Roy’s aunt, Becky Maki, said afterward outside court. “It’s been hard to live out the details of his death over and over again.”

But Roy’s family feels that justice has been served, Maki said, adding that the only good that may have come from his suicide is a new focus on mental illness.

“Conrad will be forever missed. ... His life mattered,” she said, a tremor in her voice. “Conrad, we love you.”

Roy was 18 and had been accepted to Fitchburg State University when the Mattapoisett teen fatally poisoned himself in the parking lot of a Fairhaven Kmart on July 12, 2014, by filling his pickup truck with carbon monoxide while talking with Carter by phone and text message. When he had second thoughts about killing himself, Carter ordered him to “get back in” the pickup, the text messages showed.

She was convicted in 2017 for her role in Roy’s suicide but remained free while her lawyers appealed her conviction to the state’s highest court, which denied the appeal last week. The Supreme Judicial Court rejected arguments that her text messages and cellphone calls with Roy were forms of free speech protected under the First Amendment. The SJC also denied her lawyers’ emergency motion Monday seeking further delay of her sentence.

“Today has been a long time coming,” Assistant District Attorney Maryclare Flynn said. “As always, our sympathies remain with the family of Conrad Henry Roy III. ... We are very content with what happened today in court.”

Joseph P. Cataldo, one of Carter’s lawyers, said the case “legally is not over,” adding that their First Amendment arguments are “still ripe” and should be addressed at the federal level.

Cataldo also said his client suffered from anorexia and depression at the time of her final conversation with Roy.