Edith Davis, 91, mother of First Lady Nancy Reagan, widow of Chicago neurosurgeon Loyal Davis and Broadway actress in her youth, died Oct. 26 at her home in Phoenix after a stroke.

The White House, in a statement, said President Reagan and the first lady will leave for Phoenix today.

Mrs. Davis had lived in Phoenix since 1963, where she retired with her husband. The couple moved to the southwest when Dr. Davis retired as head of the surgery department at Northwestern University. He died in 1982 at the age of 86.

Mrs. Davis, often known by her nickname of "Lucky," was the ninth and last child of Sarah Whitlock and Charles Edward Luckett of Petersburg, Va. Her father worked for the Adams Express Co., and was transferred to Washington, D.C., where she spent her childhood.

Throughout her life, Mrs. Davis was known for her vivacious, outgoing style and kindness to those in need.

"They broke the mold after they made my mother," Nancy Reagan wrote in 1984. "If I could be half the woman she is, I'd be happy . . . . " Her daughter described her as having a "delicious, wicked, wonderful sense of humor" and a "fierce loyalty to her family."

Mrs. Reagan wrote that her mother, a budding actress, got her first break at age 14 when her brother Joe gave her a job in a theater he ran. The singer Chauncey Alcott was to appear with his sister as an accompanist, but she fell ill.

Edith's brother took her to see Alcott, who asked whether she played the piano. She replied in the affirmative, even though she had no idea how to play, and was hired.

"That day she went out and bought a toy piano and practiced 'My Wild Irish Rose' all night," Mrs. Reagan related in the remembrance she wrote. "The next evening, at the opening, no one was the wiser. She went on to appear with many of the theater world greats."

Her career on the stage included appearances in New York with George M. Cohan and Spencer Tracy, who later became a close friend. She also worked with Walter Huston, Zasu Pitts, David Belasco, Louis Calhern and Ella Nazimova, the actress who became her daughter's godmother.

The young actress was married briefly to Kenneth Robbins, a New Jersey businessman, but the union broke up shortly after Nancy's birth, and the couple later divorced.

She was forced to tour in plays to support herself and her daughter, and entrusted Nancy to her sister, Virginia Galbraith, in Bethesda. She was able to spend time with her daughter only during her prolonged engagements on Broadway.

Her life changed dramatically after her marriage on May 21, 1929, to Dr. Davis, who adopted Nancy when she was 14. Mrs. Davis gave up her acting career and devoted herself to her husband, family and community work.

After Loyal Davis died, Mrs. Reagan helped her widowed mother move into an apartment in the Biltmore Estates in Phoenix.

When she and the president traveled from Washington to their ranch near Santa Barbara, Calif., Mrs. Reagan frequently stopped to visit her mother, who in her later years used a wheelchair.