BOSTON  — Michelle Carter, the woman convicted of manslaughter for urging her suicidal boyfriend to kill himself in text messages that included, “Just do it, babe,” was released from jail Thursday after more than three months was shaved from her sentence for good behavior.

Carter, 23, walked out of the Bristol County jail in Dartmouth, Massachusetts, wearing the same white blazer, dark slacks and a dark turtleneck she wore last February, when a judge ordered her to begin serving a 15-month sentence.

The Plainville native didn’t speak as two sheriff’s office staffers helped carry three bags filled with her belongings and escorted her to a waiting car. She now must serve five years of supervised release.

Carter’s lawyers said the family has no plans to speak about their daughter’s release, but the family of her late boyfriend, Conrad Roy III, has voiced criticism.

“The sheriff should serve the rest of her time,” Roy’s grandfather, Conrad Roy, told The Boston Herald this week, referring to Bristol County Sheriff Thomas Hodgson, who oversees the jail. “He lets her go because she’s a good girl? She’s not a good girl.”

Hodgson said Thursday he understood how Carter’s release could be painful for Roy’s family and others.

But he said Carter had been a model inmate who stayed out of trouble and participated in jail programs, which allowed her to accrue time off her sentence.

Carter’s release comes after the U.S. Supreme Court declined last week to hear her lawyers’ appeal of her involuntary manslaughter conviction in Roy’s 2014 death.

It also comes after she was denied parole in September. State parole board members said in their decision that they “remain troubled” that Carter not only encouraged Roy to kill himself, but also actively prevented others from intervening.

Carter’s case garnered national attention, including an HBO special, as it raised thorny legal questions about free speech and provided a disturbing look at teenage relationships and depression. It also sparked legislative proposals in Massachusetts to criminalize suicide coercion.

In text messages sent in the days before Roy’s death, Carter encouraged him to follow through with his suicide plan and chastised him when he didn’t.

“The time is right and you are ready ... just do it babe,” Carter, who was 17 at the time, wrote in a text the day Roy, 18, killed himself.

A judge determined Carter caused Roy’s death when she ordered him in a phone call to get back into his parked truck, which he had rigged to fill up with deadly carbon monoxide. The phone call wasn’t recorded, but the judge relied on a text Carter sent a different friend in which she said she had told Roy to “get back in.”

Carter opted for a bench trial, an unusual legal strategy that meant a judge decided her fate rather than a jury. She also did not testify in her defense at the trial.

The state’s highest court upheld Carter’s conviction last February and she was ordered to begin serving her jail sentence.

“After she convinced him to get back into the carbon monoxide filled truck, she did absolutely nothing to help him: she did not call for help or tell him to get out of the truck as she listened to him choke and die,” Justice Scott Kafker wrote in the state Supreme Judicial Court’s decision.

Carter and Roy both lived in Massachusetts but met in Florida in 2012 while both were on vacation with their families. Their relationship consisted mainly of texting and other electronic communications. Both teens had depression, and Roy had made suicide attempts.

Carter’s lawyers argued in their Supreme Court appeal that the conviction should be thrown out because it was an “unprecedented” violation of their client’s First Amendment rights that suggested “words alone” are enough to hold someone responsible for another person’s suicide.

The lawyers also argued that there was simply not enough evidence to prove Carter urged Roy to get back in his truck to die, or that he would have lived if she had called for help or taken other actions to try and save his life.

A case echoing Carter’s is playing out in a Boston court.

Prosecutors say former Boston College student Inyoung You drove her boyfriend Alexander Urtula to kill himself in a toxic relationship that included thousands of abusive text messages.

You, 21, has pleaded not guilty to involuntary manslaughter.