For Katie Holmes, It's 'a Real Gift' to Hail Troops

She just took in the "American Idol" finale, and this weekend, Katie Holmes will be on hand for an equally all-American event.

Holmes is among a clutch of stars performing in tonight's 20th anniversary National Memorial Day Concert broadcast from the West Lawn of the U.S. Capitol on PBS (8 p.m. ET, check local listings). She plays the sister of an Iraq war veteran, Jose Pequeno, who suffered a traumatic brain injury in combat. Pequeno, his sister, Elizabeth, and his mother, Nellie Bagley, will be in the audience. Gary Sinise and Joe Mantegna co-host.

"It's important to tell these stories and honor the sacrifice and service of these men and women and their families," says Holmes, who has never worked with the armed forces community before. "It's a real gift to be able to portray an American of such strength. I'm excited. I want to do justice to her story."

She'll get help re-enacting a veteran's family from an acting veteran, Dianne Wiest, who tapped her to participate in the concert and with whom she co-starred in the Broadway production of "All My Sons." Though they have spoken, the two haven't seen each other since the show closed in January.

"She's amazing," Holmes says. "She's an extraordinary actress and an extraordinary woman — so kind and generous. I love her."

The feeling is mutual. "There is something courageous and deeply giving about Katie, and there is a modesty and grace to her generosity," says Wiest, who portrays Bagley. "The remarkable woman she plays in (the concert) will be well-served."

Though Holmes has never performed in front of the hundreds of thousands estimated to watch the concert, she'll have a guaranteed cheering section: her husband, Tom Cruise, and daughter, Suri. "They're very excited," she says.

This summer, the trio travel much farther than Washington, D.C. — to Melbourne, Australia. The family is relocating there for three months while Holmes shoots Don't Be Afraid of the Dark, her first film lead since getting married.

"I'm really looking forward to it," says Holmes, who plays half of a designing couple who are restoring their old New England house. It will be director Troy Nixey's first full-length feature. Guillermo del Toro is producer and co-screenwriter.

Based on a 1973 TV movie, "Don't Be Afraid" is "really character-driven," Holmes says. "It's really her journey becoming a mother," unexpectedly, to her boyfriend's daughter. "In the midst of that, there's unexpected scares."