NEW YORK — On the day his mother died, celebrated actor Sir Michael Redgrave had a matinee and an evening performance to give as Hamlet. Backstage at the theater, he sobbed and sobbed and sobbed. Then he went out front. "And he did two of the greatest Hamlets he ever played."

Lynn Redgrave relates this tale about her father as a way of explaining the family's indomitable work ethic. Theater to the Redgraves is what politics is to the Kennedys: family business, family birthright, family shelter.

Grasping this genetic predisposition is helpful in understanding why, at this awful moment in Redgrave history, the award-winning actress nevertheless planned to open "Rachel and Juliet," her one-woman memory play about her actress mother, on Friday in Washington at the Folger Elizabethan Theatre. With the ache still throbbing from the death of her niece, Natasha Richardson, no one would have uttered as much as a mild groan if she had canceled the weekend of performances to nurse her grief in private.

That, however, is not the Redgrave way. "Natasha would have been appalled if I didn't do this," Redgrave, 66, says by phone from her home in Connecticut. "If I could talk to Natasha, she would say, 'What's the matter with you?'

"I can't speak for others in other professions," she adds, "but very often work is an enormous solace, just keeping to the routine, showing up at work. For those of us in the theater, it's like almost a no-brainer. Because what we do has so much to do with conjuring spirits."

Redgrave and I first met in Manhattan to speak about "Rachel and Juliet" — named for her mother, Rachel Kempson, and the Shakespeare role that would beguile her all her long life — on a Saturday in mid-March. Two days after the interview, Richardson, the actress daughter of her older sister, Vanessa, would hit her head on a ski slope in Canada. And the family would be convulsed by the multilayered dislocations that come with a sudden, premature death, the clicks of a thousand cameras and the flicker of a trillion page-views around the world.

Three days after Richardson was buried in a private ceremony in Upstate New York, next to her grandmother Rachel, we talked again. And while Redgrave was not ready to disclose much of what was in her heart, she was willing to discuss how the sad event might affect what she brought to the stage.

Because she fully intended to keep her appointment with the stage.

"Rachel and Juliet" is the latest in what has turned into a cycle of solo shows about her acting family. The first, "Shakespeare for My Father," was a poignant and painful account of her relationship with her indifferent father, Sir Michael, who had so little time for her as a child that her birth did not even warrant a notation in his diary. In December 1991, that play got its start in Washington and eventually went to Broadway, where it ran for nine months and 266 performances. She later also wrote a show about her father's mother, "Nightingale."

"Shakespeare for My Father" was a reaching-out to a parent by a daughter who was never sure whether she meant as much to him as the theater did. Although she'd had a successful film and stage career, earning an Oscar nomination for her first title role, in "Georgy Girl," part of her always wondered what precinct of his consciousness she occupied.

Neither Vanessa nor her mother attended "Shakespeare for My Father" until six months into the Broadway run. But then, Redgrave recalls, her sister, with whom Redgrave had had her ups and downs, told her, "You gave me a window into your soul and also gave me a window into Dad's."

There had been no void between Redgrave and her mother, who died in 2003 at 92. "I was very, very close to my mother," Redgrave says. "I was the beloved third baby." (Her elder brother, Corin, works as an actor chiefly in Britain.) From Redgrave's description, the play sounds as if it is a tribute to a gifted actress who did not achieve as much as she might have.

When Kempson died in May 2003, Redgrave was working off-Broadway in a production of Alan Bennett's "Talking Heads." She took off the matinee. But she was back in the show the next day.

She was happy to have been back on the stage, in the play, on that day. "Such a wonderfully laugh-packed piece of writing," she says on the phone, with warmth in her voice. "Somehow, I guess that's why we're actors."