Lior Moller did not know the Rockville mother who was told last month to go into a women's restroom at the Hirshhorn Museum to breast-feed her daughter.

But on Saturday morning, she joined about 150 parents and babies at the museum to draw attention to the woman's plight, encourage women to exercise their federal right to breast-feed in public and remove the stigma associated with nursing in public.

"I'm here to show that breast-feeding is normal and a right," said Moller, wearing a T-shirt made for the event that read "Don't Be Lactose Intolerant."

As volunteers at the "nurse-in" handed out laminated cards with information about breast-feeding rights to parents, the Alexandria City Council amended its indecent-exposure law Saturday to exclude breast-feeding.

"In our efforts to be a more family-friendly community, we have to take on all aspects of what that means, including doing right by moms," said council member Rob Krupicka (D), who proposed the amendment.

The council plans to pass a special proclamation this month promoting breast-feeding as part of the city's health and wellness initiatives.

A 2007 Inova Health Systems study said 43.5 percent of Alexandria's 2- to 5-year-olds were overweight, the worst in the region, said Brian Moran, chairman of the Partnership for a Healthier Alexandria.

"This is really about the promotion of a healthy lifestyle," said Vice Mayor Kerry Donley, who said breast-feeding leads to improved nutrition and increased immunities for children.

The city has rooms available for its employees to pump or feed and policies in place. Those efforts will be spread throughout the city's facilities, including pools and recreation centers, officials said.

"Isn't that awesome," said L.J. Pelham, organizer of the demonstration, referring to the Alexandria legislation. "It's unlikely that there have been a lot of women called on that law, but it's awesome, especially that it's happening today."

Pelham said the grass-roots demonstration at the Hirshhorn, which drew mothers, fathers and their babies from across the Washington region, was a "teachable moment" to empower mothers and get people to refrain from shaming women when they exercise their right to breast-feed in federal buildings and on other federal property.

The demonstration wasn't a protest against the museum, she said. "It's not to blame, or shame or inflame," Pehlham said. Moller said she considered it "a celebration of mothers and babies, more than anything else."

So there were no chants, no placards - just babies crawling along the floor. Some children were in strollers. Others were cradled in their mothers' arms while being nursed.

The event was organized after stay-at-home mother Noriko Aita was told by a Smithsonian guard Jan. 30 to leave a bench and go to a women's restroom to nurse her 11-month-old daughter, Elaine. When she returned after finding no place to sit in the restroom, another guard told her to sit on the toilet.

Aita, who received an apology from the museum, said Saturday that she hoped the demonstration would not only raise awareness about nursing mothers' rights but also ensure that other women won't have the same experience she did.

"I didn't know the law," Aita said. "This can never happen again. . . . I don't want my daughter to have this trouble."

Chalaine Lawrence, who gave birth to her daughter, Taliyah, six weeks ago, said she was shocked to hear about what happened to Aita.

"Would you want to eat your lunch in the restroom?" Lawrence asked. "I'm here to stand up for all breast-feeding moms."

Chris Garosi, one of many fathers at the "nurse-in," said he came to support the effort.

"We can't do a lot," he said. "We can't do what do what they can do. But we want to support."

Garosi said breast-feeding has economic and environmental advantages, as well as nutritional benefits.

According to an April study in the American Academy of Pediatrics journal, the United States would save about $13 billion and 911 babies' lives annually if 90 percent of mothers breast-fed exclusively for six months.