WASHINGTON — Physically and emotionally bullied as a fourth-grader, Jackie Andrews is fighting back.

She's doing so not with taunts or fists but with an anti-bullying campaign the 16-year-old high school junior is developing with her sister Josie, 14, that might soon get a national audience.

Wednesday, the Andrews sisters, from Haddon Heights, appeared before a House Education and Labor subcommittee that invited them to speak as part of a hearing on ways to prevent bullying. The panel included one particularly interested lawmaker: their father, Rep. Rob Andrews, D-Haddon Heights, who helped arrange their appearance.

The girls' message is simple: Bullying happens because bystanders don't intervene.

"A future without bullying is dependent on the 99.9 percent of the people who can make a difference, the people who know that bullying is wrong but who thus far have done nothing to stop it," Jackie told the panel. "In my book, this 99.9 percent is as bad as the bully himself because the bully doesn't know better. They do."

More than one in four youths in the U.S. are estimated to be involved in bullying as either a bully, a victim or both, according to the National Youth Violence Prevention Resource Center. Experts warn that bullying, if unchecked, can lead to greater violence.

"These days, bullying and school violence can have dire consequences," said Rep. Carolyn McCarthy, D-N.Y. "Often, acts of bullying can extend beyond the halls of our school buildings, and (it) has found a new home on the Internet."

Sirdeaner Walker knew that school bullies were tormenting her son Carl. She didn't know how much he had suffered until April 6, when she found that her 11-year-old had hanged himself in his bedroom with an extension cord.

"I did everything a parent is supposed to: I chose a 'good' school. I joined the PTO. I went to every parent-teacher conference," the Springfield, Mass., mother told lawmakers. "I called the school regularly and brought the bullying problem to the staff's attention. The school did not act. Teacher did not know how to respond."

Activists want Congress to get involved by increasing money for school counselors, requiring better training of educators and improving the data collected on school violence to get a more accurate picture of what's happening.

The Andrews sisters have their own remedy.

Jackie has taken three years to create an anti-bullying curriculum tailored for grades three through eight. She said she's in talks with an Internet education network, ePals, that might be interested in offering the program to schools.

Josie, a rising ninth-grader, has written a screenplay and songs for a musical movie, "Milo J High," about bullying. Later in the day, she performed some of the songs at Six Flags America in Bowie, Md.

An independent movie producer has expressed interest in making the film, Rob Andrews said.

Josie said some of the programs in schools don't work because they're created by adults who don't know the best way to reach kids.

They "aren't realistic," she told the panel. Her message is effective, Josie said, because it's "the language of a 14-year-old girl who can relate to a 10-year-old and what she's been through."

At one point, Rob Andrews mused about the rare opportunity he got to cross-examine his daughters in a public hearing.

"Every parent of a teenager welcomes that opportunity," he joked.

Reach Ledyard King at lking@gannett.com