Miriam Georgia Hoy Kauffmann, 81, the widow and mother of presidents of The Washington Star, died of congestive heart failure Friday at her home in Washington.

Her husband, Samuel Hay Kauffmann, who was president of The Star from 1949 to 1963, died in 1971. A son, John Hoy Kauffmann, who was chief officer of the newspaper from 1968 to 1974, died of cancer Tuesday.

Mrs. Kauffmann was born in Albany, N.Y. She and her husband had known each other since childhood. Their families had neighboring summer enclaves on a lake in the White Mountains of New Hampshire.

She came here after her marriage in 1920, and for many years was active in Washington social life.

Like her husband, Mrs. Kauffmann participated in civic activities. She had served on the boards of the old Garfield and Emergency hospitals. After they were merged along with Episcopal Hospital into the Washington Hospital Center, Mrs. Kauffmann served on the board of the center. She also had been active with the American Red Cross.

She is survived by a son, Samuel H. III, of Palo Alto, Calif.; a daughter, Joan Lamphere, of Bethesda, 20 grandchildren and six great-grandchildren.

The family suggests that expressions of sympathy be in the from of contributions to Washington Hospital Center.