It would make for a powerful story, except it wouldn't be completely true.
Terry, 54, will join hundreds of thousands of marchers in Manhattan, most of them brought there by shared opposition to the war in Iraq. Yet long before the death of Laura Rockefeller, a 1981 Syracuse University graduate, Terry was an activist for peace.
She figures she would have marched in New York even if her family, no relation to the famous Rockefellers, had been untouched by the terrorist attacks. Terry is a longtime member of Amnesty International, a global organization dedicated to justice and human rights.
Even so, if Laura hadn't been killed at 41, Terry doubts she would have traveled to Iraq just before the American occupation, a trip on which she spoke with Iraqi women who'd lost husbands or children to acts of war. She doubts she would have met with survivors of the atomic blasts in Hiroshima and Nagasaki, survivors who've dedicated their lives to world peace.
Those encounters happened after Terry joined Peaceful Tomorrows, a group created by family members of some of the victims of Sept. 11. The organization is dedicated to better global understanding. Terry said it's helped her remember that the United States is only one of many nations where innocents routinely suffer for being in the wrong place at the wrong time.
That reality, she said, is too often missing from our national debate.
"I would give anything to have Laura be alive," Terry said. "But 3,000 people died in America. At last count, tens of thousands of people have been killed in Afghanistan and Iraq. If we're truly a world leader, we'd understand that all those lives are equal. The families of all those civilians killed in my sister's name are just as devastated as my family was."
On the eve of the Republican National Convention, Terry will march today with a group called "9-11 Families Against the War." As far as she's concerned, the protest should be a peaceful means of showing the world that many Americans are opposed to their own government's invasion of Iraq.
None of that means she offers pardon to the killers of her sister.
"I'm really angry," said Terry, who lives with her husband and daughters in Massachusetts. "I'm angry because my sister had a lot of her life to live, and I needed her around to be my buddy for the rest of my life, and my daughters deserved to have an aunt at their graduations and their weddings and whatever happens in the future.
"But I'm also not going to stoop to saying that killing in revenge does any good. What would make a real difference to me is truth and justice."
For Terry, a documentary filmmaker, any visit to New York carries reminders of Laura, who had starring roles as an SU student in such local productions as "Gypsy" and "Carnival."
After college, Laura settled in Manhattan. Her passion remained the performing arts, from summer stock to children's theater, although she still needed a way to pay the rent. Laura often worked for a company that helped coordinate business conferences. On Sept. 11, her job took her to Windows on the World, a restaurant atop the trade center.
"The last conversation I had with her was silly," said Terry, who was nine years older than her sister. "She'd joined one of those community gardens in western Massachusetts. She'd gotten a crate of cucumbers, and she was wondering what she could do with five pounds of cucumbers."
They made plans to see each other, then said goodbye.
Laura didn't mention the job she had lined up at the twin towers. On the day of the attacks, Terry kept calling her sister's apartment. She told herself that everything was fine, until one of Laura's friends called her in the afternoon.
Terry's parents are elderly. For many weeks, their surviving daughter helped them maneuver through the legalities of losing a grown child to a senseless, violent death.
Despite her grief, Terry never thought the best answer was a war.
"On Sept. 12, we had a chance, we had an opportunity," Terry said. She said the United States, as the recipient of global sympathy, could have united the world behind a humanitarian effort to attack poverty, ignorance and hunger - the basic recruiting tools of terrorists.
"Instead, what I feared has happened," Terry said. "We made a great show of regime change, but we haven't changed the lives of those individuals liable to turn toward terrorism out of desperation."
With all that in mind, she'll be in New York today. She knows many Americans might be baffled as to why someone who's lost so much to heartless killers would march against what her own government maintains is an eye-for-an-eye response. Terry offers many answers, but this one might say it best:
If Laura could be here, Terry said, she thinks that she'd be marching, too.