Maru Montero’s young dancers know that of all their performances each year, none is as special as the one they give the first week of every May.

As Montero puts the girls through rehearsals of the zapateado, the Mexican-born folk dancer urges them to focus on staying in sync, on shaking their skirts and on smiling.

On Saturday, they will be featured in the National Cinco de Mayo Festival, and all that they have learned under her tutelage will be on display.

“I won’t be in front of you when you are onstage,” Montero reminds the young girls. “Big smile! Always remember to smile!”

Montero, 50, started the Cinco de Mayo celebration 20 years ago with performances at local schools. Now thousands come to the free festival, held at the Sylvan Theater at the base of the Washington Monument.

“She wanted to have a festival where the children could talk in Spanish and English, and where they could learn about their culture,” said her younger brother, Marcos Montero, who learned to dance with her.

With music, games and sombreros, the event became a taste of Mexican heritage. Over the years, as the area’s Hispanic community grew more diverse, Montero expanded the presentations to include folklore from across Latin America.

“On Cinco de Mayo, we are all Latinos,” Montero said. “Of course, we celebrate a very important battle that the Mexicans won against the French, but this is everybody’s holiday. It is more widely celebrated in the United States than it is in Mexico.”

On Cinco de Mayo — Spanish for May 5 — Mexico remembers the courage of 4,000 Mexican soldiers who defeated 8,000 French troops in the state of Puebla on May 5, 1862. The victory became a symbol of unity and identity.

In the United States, the day is celebrated with festivals and parades, beauty pageants and cooking contests. In Washington, Montero’s festival gives a stage to local folklore talent and young children of different ethnic backgrounds.

A native of Oaxaca, Montero became passionate about folklore in sixth grade when she joined an amateur dance group.

“I danced and danced and danced. . . . I loved the discipline and the camaraderie in the group,” Montero recalled. “I learned ballet, contemporary dance and Latin American folklore.”

In high school, she auditioned for Amalia Hernandez, an icon of Mexican folkore and founder of the Ballet Folklorico de Mexico. Soon after, she became a lead dancer with the Ballet Folklorico, which took her to perform across Mexico and abroad.

In 1987, Montero settled in Washington with her husband, Peter Copeland, an American journalist she met in Mexico City. Her plans were to go to college and find another career, but she soon was back on the dance floor.

“I brought only a pair of dance shoes with me, because I had other ideas in mind,” Montero said. She took English classes, got her GED and taught Spanish for a year.

She took a chance to do a Cinco de Mayo performance at a local school, and that led to teaching dance after school and to forming the Maru Montero Dance Company. When she didn’t have a place to rehearse, she would seek out space at churches and schools.

“She is a success story,” said Sonia Gutierrez, the founder of the District’s Carlos Rosario International Public Charter School — formerly the Carlos Rosario Adult Education Center, where Montero learned English and held dance rehearsals.

“She started out with nothing, no English and no place to rehearse. Nothing,” Gutierrez said. “She learned English, formed her company and took off. And now she is giving back to the community.”

Sometimes alternating between English and Spanish, Montero teaches Latin American folklore — and contemporary dances — to area children and adults. She and her students perform at schools and public libraries and have participated in special events at the White House and the Kennedy Center.

These days, Montero’s home remains a headquarters for Cinco de Mayo supplies. She has made the event a family affair. Her children, Isabella, 19, and Lucas, 17, help coordinate volunteers and event activities. Her sisters travel to Washington with their daughters and wear traditional outfits from their home town in Oaxaca.

Often struggling to get festival sponsors, this year she partnered with the League of United Latin American Citizens, which is bringing salsa sensation Luis Enrique and a health fair to the festival.

“She is a real artist,” said Alfonso Prado, who has worked with Montero for 14 years and helps organize the festival. Prado credits Montero with helping shape many of the area’s Latin American folklore dancers. “When she listens to a song, she starts envisioning the choreography in her head, and she doesn’t give up until she sees her idea on stage.”

“She demands you to give 100 percent, and she demands even more of herself,” Prado said. “That’s why the girls dance as good as they dance. She requires us to be better dancers and better people. That’s how we have learned.”

Irene Chamorro-Beckenhauer, 11, who has been dancing with Montero for three years, says she enjoys the festival. “It’s exciting to be onstage when everybody is watching you,” she said.

Irene, whose mother is from Peru and whose father is from Germany, said Montero has been a good teacher: “When you are not good at something, she helps you, and she doesn’t get frustrated or anything.”