Michelle Obama is a wartime first lady, a fact that she has acknowledged since the early days of her tenure by campaigning on behalf of military families.

Her outreach to veterans continued Wednesday as the nation paused to remember the terrorist attacks of Sept. 11, 2001. Obama spent her afternoon at the new USO center at the Army’s Fort Belvoir.

At the USO Warrior and Family Center, a spacious facility built to serve the families of wounded soldiers, Obama said she had come to “shine a bright light on the great work” of the USO and the new family center, which is the largest ever to support wounded troops and their families.

Carrying a basket of cookies decorated in the likeness of the Obama family’s new Portuguese water dog, Sunny, Obama quickly moved into the comfortable rapport she has developed with military families.

“We’re so proud of you guys,” she said to the 15 elementary-school-aged children seated at tables before her. “Do you realize that you guys are heroes?”

A crying toddler whined in the background, and other children continued making crafts and chatting as Obama spoke. She smiled at the noise.

“I know there are mothers back there saying, ‘Be quiet,’ ” Obama said to parents in the rear of the room. “Let them be.”

Then she asked the children whether she and her guest Gary Sinise, the actor famous for his portrayal of Lt. Dan in “Forrest Gump,” could help them with their arts and crafts.

Obama joined a table near the front, taking a seat next to chatty 6-year-old Abigail and 7-year-old Andrew Starr. They helped her trace her palms onto red and blue construction paper.

“You’re doing a great job,” she told them.

The children talked to Obama about sports, and she asked whether they knew what they wanted to be for Halloween.

“Maybe you could come trick-or-treat at the White House,” she said.

“Really?” the Starr children replied.

In the early days of her efforts, Obama was clear to acknowledge that she had no direct experience with military service. She often points out that she, like most Americans, has watched veterans return from Iraq and Afghanistan but has not sent immediate family members off to battle. Service members represent only 1 percent of the population.

Obama’s decision to make helping military families one of her key initiatives came from hearing their stories. In 2011, she joined with Jill Biden, who had sent her son Beau off to Iraq, and started Joining Forces. The first lady has since asked corporations to hire veterans and implored state officials to make it easier for military spouses to transfer work-related credentials from state to state.

Obama ended her day on Fort Belvoir by meeting privately with wounded service members and their families, and holding a roundtable with their caregivers, away from the media. In the past 41 / 2 years, she has held many such conversations.

Those discussions have likely shaped her worldview. As President Obama has grappled publicly with whether to strike Syria, he has acknowledged talking it over with the first lady. In an interview with NBC’s Savannah Guthrie, he said his wife has strong opinions on the issue.

“And if you ask somebody, if you ask Michelle, ‘Do we want to be involved in another war?’ The answer is no,” he said.