Penelope J. (Penny) Brush, 52, a dental hygiene technician, died Saturday at her home in Rockville after a long illness.

Born in Johannesburg, South Africa, where her father was the American Trade Commissioner to the Union of South Africa, Mrs. Brush came to this country as a child and graduated from Woodrow Wilson High School and Temple University.

She worked as a dental hygiene technician in Washington for many years while keeping active in the community affairs of Rockville. She was involved in Democratic Party politics and was a member of the St. Francis Episcopal Church in Potomac since its founding. As a member of the St. Francis congregation she was head of the Altar Guild for several years.

She was also associated with the Big Brothers Organization of Philadelphia and the D.C. Public Schools.

Surviving are her husband, James W., of the home; three children, Mrs. Scott A. Perando of Gaithersburg, Charles E. Brush of Washington, and Joseph T. Brush of Rockville; a sister, Mrs. John F. Garges of Washington; and a brother, Dr. Robert T. Stevenson of Springfield, Mo.

The family suggests that expressions of sympathy be made in her memory to the Cancer Research Institute of Oral Roberts University in Tulsa, Okla., 74171 or to the American Cancer Society.