Cecily McMillan, an Occupy Wall Street protester and former Atlanta resident, currently is in custody at New York City’s Rikers Island, awaiting sentencing after being convicted of assaulting a police officer.

The 25-year-old graduate student faces a possible seven years in prison, which may be the most serious punishment levied against any of the hundreds of Occupy protesters arrested since demonstrations began in 2011.

That status has made McMillan the focus of international attention. Supporters from around the country and abroad have taken up her case, though nowhere with greater fervor than in Atlanta.

“I think she’ll win on appeal, I really do,” said Harlon Joye, one of McMillan’s many Atlanta friends and relatives who anxiously watched the trial and are awaiting her May 19 sentencing.

Joye, 81, is McMillan’s step-grandfather and a longtime Atlanta activist. He was among the founders of Students for a Democratic Society and worked with Bayard Rustin to help organize marches on Washington in the late 1950s and early ’60s. He was one of the architects of the 1963 march that featured the Rev. Martin Luther King Jr. and his “I Have a Dream” speech.

Joye was married to Sandra Heartfield, McMillan’s grandmother, for 28 years until her death last year. Heartfield and Joye operated the Heartfield Manor B&B in Inman Park, a rambling, cedar shake-wrapped Arts and Crafts mansion on Elizabeth Street.

A dedicated agitator for social justice, McMillan participated in Wisconsin protests in 2011, and was studying social movements at the New School in Manhattan when she was propelled into the headlines.

On March 17, 2012, McMillan attended a gathering at New York’s Zuccotti Park commemorating the six-month anniversary of the first Occupy protests.

According to Joye, that evening she sent a photo of her St. Patrick’s Day outfit to her father — a short green skirt and a form-fitting green top — and he wrote her back, saying, “I don’t think you want to get arrested in that.”

“She said, ‘I don’t intend to get arrested,’” Joye said. “She was going out to have a drink with friends.”

Then McMillan came in contact with New York police Officer Grantley Bovell, who was clearing protesters from Zuccotti Park.

She testified that he grabbed one of her breasts from behind, and that she whirled in fear, striking him in the face with her elbow. He testified that he was simply trying to escort her from the park. She has published photos online showing dark bruises on her breast. Photos from the event show McMillan screaming, apparently in pain, her clothes disheveled.

During the trial a number of Atlanta residents traveled to New York to observe, including L. Nyrobi Moss, who calls herself the “house mother” at 7 Stages, where McMillan was once an intern.

“Cecily was organizing movements from way back,” said Moss, a 7 Stages board member and organizer of the theater company’s summer program, in which McMillan also participated. “She has the gift of persuasiveness — or gab.”

McMillan’s father, James McMillan, credits Joye with inspiring Cecily to pursue a life of activism.

In the late 1980s James McMillan was living in Inman Park, next door to Joye and Heartfield, when Cecily was born. He moved the family to Oregon and Texas as his work required, then brought them back to Atlanta when Cecily was a teenager.

She attended Decatur High School and Grady High School. When her father moved back to Texas, she lived with Moss in East Atlanta so that she could complete her high school education here.

She also confided in Moss during the trial.

“If I go to jail …” she began one conversation.

“You are not going to jail for this,” Moss responded. “Stop exaggerating.”

Now that McMillan could spend several years in jail, Moss is coming to grips with a sobering possibility:

“I was wrong.”