Nancy Bell Brady, 63, who was a confidential secretary to several high-ranking federal officials, died June 20 at Johns Hopkins Hospital of complications following a bone marrow transplant.

Mrs. Brady, who lived in Arlington, was born in Cassville, W.Va. She began her federal career in 1957 as a Pentagon secretary. Beginning in 1962, she served as secretary and administrative aide to four secretaries of the Air Force, including Harold Brown, whom she later served when he was secretary of defense.

She left federal service in 1985 to work for Brown at the Johns Hopkins School for Advanced International Studies and later at the Center for Strategic International Studies, where she worked until her death.

In 1991, Mrs. Brady helped found the national capital area chapter of Transplant Recipients International Organization, a service organization for people who have received organ transplants or who are candidates for the procedure and for their families, friends and organ donors.

She became membership chairman of the organization. Her husband was a heart transplant recipient.

Her marriage to Richard Whiddon ended in divorce.

Survivors include her husband, whom she married in 1966, Claude Brady of Arlington; a daughter from her first marriage, Cynthia Green of Highland, Tex.; three brothers; and seven grandchildren. A son from her first marriage, Richard Whiddon, died in 1989.