Princess Diana visited two first ladies Friday - one who lives in the White House and another, only 3 years old, who is infected with the AIDS virus.

The younger "first lady" earned her nickname because she was the first child placed at Grandma's House, a home for children with the deadly virus.The little girl, dressed in bright pink overalls for the occasion, grabbed Diana's hand when they were introduced. The princess scooped her up, carried her upstairs during a tour of the Victorian row house, and readily agreed when she asked to ride around the block in Diana's dark green Rolls-Royce.

As cameras flashed and whirred, the princess stepped out of the car with "the first lady" in her arms - a symbolic picture that gratified the founders of Grandma's House, who have kept its location unpublicized out of concern about prejudice and fear.

"That kind of picture . . . a person of her stature coming . . ." said the Rev. Debbie Tate, president of a crisis housing organization that runs Grandma's House. "It shows that it's all right to love a person with AIDS, it's all right to care about a person with AIDS, it's all right to hug a person with AIDS . . . It won't hurt you."

Tate said the little girl had not been diagnosed yet with full-fledged AIDS, but the virus was progressing. Once that diagnosis is made, she said through tears, "the first lady" could be expected to live about a year.

Diana's whirlwind trip, her second solo visit to the United States, ended less than 24 hours after she arrived in the country.

She attended a gala Thursday night to benefit Grandma's House and ballet companies in Washington and London, and had coffee Friday morning at the White House with Barbara Bush and others before her motorcade went to the children's residence.

President Bush appeared for the last 10 or 15 minutes of the 35-minute White House meeting, according to British Embassy spokesman Francis Cornish. He said Bush congratulated Diana on her work and compared her causes to those he honors with his "thousand points of light" program.

The princess concluded her visit by cutting a red ribbon to open Grandpa's House, a nearby house that will double the program's capacity from six to 12 children. The brief ceremony was witnessed by Mayor Marion Barry and his wife, Effi. Diana strode across the street to shake hands with well-wishers, creating an instant commotion, and then she was gone.

"It touched my heart. She was very, very warm, very much a caring person for the children," said Joan McCarley, Tate's sister and the executive director of Grandma's House.

McCarley said the money raised by the gala - more than $100,000 - also meant a lot to her small operation.